As filed with the Securities and Exchange Commission on May 14, 2007

Registration No. 333-137124

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

AMENDMENT NO. 4
TO
FORM S-1
REGISTRATION STATEMENT
UNDER
THE SECURITIES ACT OF 1933

CLEAN ENERGY FUELS CORP.
(Exact name of registrant as specified in its charter)

3020 Old Ranch Parkway, Suite 200
Seal Beach, CA 90740
(562) 493-2804
(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant's Principal Executive Offices)

Andrew J. Littlefair
President and Chief Executive Officer
Clean Energy Fuels Corp.
3020 Old Ranch Parkway, Suite 200
Seal Beach, CA 90740
(562) 493-2804
(Name, Address, Including Zip Code, and Telephone Number, Including Area Code, of Agent for Service)

Approximate date of commencement of proposed sale to the public: As soon as practicable after this registration statement becomes effective.

        If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box.    o

        If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

        If this form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

        If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    o

        The registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the registrant shall file a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, as amended, or until this registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

SUBJECT TO COMPLETION, DATED MAY 14, 2007

The information in this prospectus is not complete and may be changed. We and the selling stockholders may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

Clean Energy Fuels Corp. 20,000,000 Shares of Common Stock

Investing in our stock involves a high degree of risk.
See "Risk Factors" beginning on page 7.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed on the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

Simmons & Company International

The date of this prospectus is                          , 2007

The Natural Gas Vehicle Advantage
		The Market for Natural Gas as an Alternative Fuel Natural gas fuels are well suited for use by vehicle fleets which consume large amounts of fuel and refuel at centralized locations. Cheaper Natural gas vehicle fuels are cheaper than gasoline and diesel. Cleaner Use of natural gas as a vehicle fuel creates less pollution than use of gasoline or diesel. Domestic In 2006, an estimated 98% of the natural gas consumed in the United States was supplied from the United States and Canada.

TABLE OF CONTENTS

              You should rely only on the information in this prospectus. We and the selling stockholders have not authorized anyone to provide you with different information. We and the selling stockholders are offering to sell, and seeking offers to buy, shares of our stock only in jurisdictions where offers and sales are permitted. You should assume that the information in this prospectus is only accurate as of the date of this prospectus. Our business and financial condition may have changed since that date.

PROSPECTUS SUMMARY

              This summary should be read together with the more detailed information in this prospectus regarding our company and the stock being sold in this offering. This summary provides an overview and does not contain all the information you should consider before investing in our stock. Please read the entire prospectus carefully, including "Risk Factors" beginning on page 7 and the "Glossary of Key Terms" beginning on page A-1.

Our Business

              We are the leading provider of natural gas as an alternative fuel for vehicle fleets in the United States and Canada, having supplied natural gas fuels to our customers since 1997. In the late 1980s, one of our founders, Boone Pickens, became convinced that natural gas had a number of advantages over gasoline and diesel as a vehicle fuel. Over the next decade and a half, Mr. Pickens and Andrew Littlefair, our CEO, were pioneers in developing this market, targeting vehicle fleets because they consume large amounts of fuel, refuel at centralized locations and are subject to increasingly stringent requirements to reduce emissions. Natural gas vehicle fuels include compressed natural gas (CNG) and liquefied natural gas (LNG).

              Messrs. Pickens and Littlefair founded our company on the premise that natural gas is cheaper and cleaner than gasoline and diesel, and that almost all natural gas consumed in the United States is produced in North America.

              Cheaper—Over the last several years, natural gas vehicle fuels have become increasingly less expensive than gasoline and diesel fuel, as the spread has increased between the price of natural gas (on a gasoline gallon equivalent basis) and the prices of gasoline and diesel. Retail fuel prices for the month of March 2007 show that the average pump price of regular gasoline, as reported by Oil Price Information Service (OPIS), was $0.89 per gasoline gallon equivalent higher than our average CNG pump price in the State of California. Tax incentives further increase the cost advantage of natural gas vehicle fuels, such as the federal Volumetric Excise Tax Credit (VETC) of $0.50 per gasoline gallon equivalent of CNG and per liquid gallon of LNG sold for vehicle use, which became effective October 1, 2006.

              Cleaner—CNG and LNG create less pollution than gasoline or diesel. Natural gas vehicles have been shown to reduce smog-causing NOx emissions by 50% or greater and particulate matter (soot) by 70% when compared to same-model diesel vehicles in South Coast Air Quality Management District engine tests. Emissions reductions are increasingly important as more stringent federal regulations effective in 2007 and 2010 will limit acceptable levels of emissions for new heavy-duty vehicles, such as buses and trucks. From well to wheels, natural gas reduces levels of greenhouse-gas emissions up to 27% for light-duty vehicles and up to 21% for medium and heavy-duty vehicles.

              Domestically available—In 2006, according to the U.S. Department of Energy's Energy Information Administration, or EIA, the United States consumed 17.1 million barrels of crude oil per day, of which 58% was imported from outside the United States and Canada. By comparison, an estimated 98% of the natural gas consumed in the United States in 2006 was supplied from the United States and Canada, making natural gas less vulnerable to foreign supply disruption. Additionally, biogas, which is sourced from waste streams, represents a renewable and domestic supply of natural gas.

              We offer a comprehensive solution to enable vehicle fleets to run on natural gas as an alternative to gasoline or diesel. We design, build, finance and operate fueling stations and supply

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our customers with CNG and LNG. CNG is produced from natural gas which is supplied by local utilities to vehicle fueling stations, where it is compressed and dispensed into vehicles in gaseous form. LNG generally is used in trucks and other medium to heavy-duty vehicles as an alternative to diesel, typically where a vehicle must carry a greater volume of fuel. LNG is natural gas that is super cooled at a liquefaction plant until it condenses into a liquid. We deliver LNG supplied by third party plants as well as our own plant to fueling stations via our fleet of 48 tanker trailers. At the stations, LNG is stored in above ground containers until dispensed into vehicles in liquid form.

              We also help our customers acquire and finance natural gas vehicles and obtain local, state and federal clean air incentives. We serve over 200 fleet customers operating over 14,000 natural gas vehicles in a variety of markets, including public transit, refuse hauling, airports, taxis and regional trucking. We own, operate or supply 172 natural gas fueling stations in 12 U.S. states and Canada. In 2006, we delivered over 68.4 million gasoline gallon equivalents of CNG and LNG and for the first three months of 2007 we delivered over 17.8 million gasoline gallon equivalents of CNG and LNG.

              We have built critical mass in our primary regions of operation and expanded into new areas through strategic investments in fueling stations and through acquisitions. Although most of our LNG is currently supplied by third parties, we also have made a significant investment in LNG production capacity in an effort to expand and optimize our dedicated sources of LNG supply. In addition to our dedicated LNG liquefaction plant in Texas, we have established relationships with four LNG supply plants in the western United States, which enable us to better serve this key region. We are also in the initial stages of constructing an LNG liquefaction plant in California to enhance our ability to serve the California and Arizona markets.

Corporate Information

              We were incorporated in Delaware in April 2001 to combine the businesses of Pickens Fuel Corp., a natural gas fuels company started by our founders in 1996, and BCG eFuels, Inc., a Canadian natural gas fuels company. Our principal executive offices are located at 3020 Old Ranch Parkway, Suite 200, Seal Beach, California 90740, and our telephone number is (562) 493-2804. Our website is www.cleanenergyfuels.com. The information on our website is not part of this prospectus.

              The "Clean Energy" name and related images and symbols are our properties, trademarks and service marks. All other trade names, trademarks and service marks appearing in this prospectus are the property of their respective owners.

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The Offering

              Except as otherwise noted, all information in this prospectus assumes no exercise of the underwriters' over-allotment option to purchase from selling stockholders up to 3,000,000 shares of our common stock.

              The number of shares of our common stock to be outstanding after this offering is based on the number of shares of capital stock outstanding as of March 31, 2007 and excludes:

•

15,000,000 shares of common stock issuable upon the exercise of outstanding warrants held by Boone Pickens at an exercise price of $10.00 per share,



•

2,401,000 shares of common stock issuable upon the exercise of outstanding options at a weighted average exercise price of $2.97 per share (of which options to purchase 2,376,000 shares of our common stock at a weighted average exercise price of $2.96 per share were exercisable), 256,144 of which will be issued upon exercise of such options by selling stockholders in connection with this offering,



•

2,825,500 shares of common stock issuable upon the exercise of options to be granted to employees at the closing of this offering at an exercise price equal to the initial public offering price, and



•

2,187,750 shares of common stock reserved and available for future issuance under our equity incentive plans.

              This offering will be made through the OpenIPO process, in which the allocation of shares and the public offering price are primarily based on an auction in which prospective purchasers are required to bid for the shares. This process is described under "Plan of Distribution" beginning on page 109.

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Summary Historical Consolidated Financial Data

              The following tables present our summary historical consolidated financial data. You should read this information together with our financial statements and related notes and the information under "Selected Historical Consolidated Financial Data" and "Management's Discussion and Analysis of Financial Condition and Results of Operations" included in this prospectus. The summary financial data below for the years ended December 31, 2004, 2005 and 2006 are derived from our audited financial statements included in this prospectus. The summary financial data for the three months ended March 31, 2006 and 2007 are derived from our unaudited financial statements included in this prospectus.

(1)

Revenue includes the following amounts:

(2)

2006 amount includes $78,712,599 of losses on derivative contracts. The contracts were assumed by our majority stockholder, Boone Pickens, on December 28, 2006. See "Certain Relationships and Related Party Transactions—Obligation Transfer and Securities Purchase Agreement with Boone Pickens" on page 96.

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The following table presents a summary of our unaudited balance sheet data as of March 31, 2007:

Adjusted Margin (Non-GAAP)

              A portion of our natural gas fuel sales are covered by contracts under which we are obligated to sell fuel to our customers at a fixed price or a variable price subject to a cap. Our policy is to purchase natural gas futures contracts to cover our estimated fuel sales under these contracts to mitigate the risk that natural gas prices may rise above the natural gas component of the price at which we are obligated to sell gas to our customers. However, from time to time, we have sold these underlying futures contracts when we believed natural gas prices were going to fall. When we sold the futures contracts, we were exposed to the economic risk of rising natural gas prices causing our fixed price or price cap sales contracts to be in a reduced margin position or in a loss position, which occurred from time to time. At December 31, 2006, we had sold all such underlying futures contracts. Effective March 2007, we may no longer sell the underlying futures contracts associated with our fixed-price sales contracts without the prior approval of our board of directors and derivative committee.

              Our management uses a measure called Adjusted Margin to measure our operating performance and manage our business. Adjusted Margin is defined as operating income (loss), plus (1) depreciation and amortization, (2) selling, general and administrative expenses, (3) derivative (gains) losses, and (4) loss on extinguishment of derivative liability, the sum of which is adjusted by a non-GAAP measure which we call "futures contract adjustment," which is described below. Management believes Adjusted Margin provides helpful information for investors about the underlying profitability of our fuel sales activities. Adjusted Margin attempts to approximate the results that would have been reported if our futures contracts would have qualified for hedge accounting under SFAS No. 133 and were held until they matured.

              Futures contract adjustment reflects the gain or loss we would have experienced in a respective period on the underlying futures contracts associated with our fixed price and price cap contracts had those underlying contracts been held and allowed to mature according to their contract terms.

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              The material limitations of Adjusted Margin are as follows: Adjusted Margin is not a recognized term under GAAP and does not purport to be an alternative to gross margin as an indicator of operating performance or any other GAAP measure. Moreover, because not all companies use identical calculations, this presentation of Adjusted Margin may not be comparable to other similarly-titled measures of other companies. We compensate for these limitations by using Adjusted Margin in conjunction with traditional GAAP operating performance and cash flow measures, and therefore, we do not place undue reliance on this measure.

              The table below shows Adjusted Margin and also reconciles these figures to the GAAP measure operating income (loss):

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RISK FACTORS

              An investment in our stock involves significant risks. You should carefully consider the risks described below, together with all of the other information in this prospectus, before making a decision to invest in our stock. If any of these risks actually occurs, our business, results of operations, financial condition and prospects could suffer. As a result, the trading price of our stock could decline and you may lose part or all of your investment.

Risks Related to Our Business and Industry

We have a history of losses and may incur additional losses in the future.

              In 2006 and the first three months of 2007, we incurred pre-tax losses of $10.8 million and $0.9 million, respectively, related to our operations, which consist of natural gas fueling activities and station operations, and derivative losses of $79.0 million and $0.0 million, respectively, combining for overall pre-tax losses of $89.8 million and $0.9 million, respectively. In 2004 and 2005, excluding derivative gains, we incurred pre-tax losses of $6.8 million and $15.2 million, respectively, related to our operations. We must continue to invest in developing the natural gas vehicle fuel market, and we cannot assure you that our natural gas sales activities and station operations will achieve or maintain profitability. If our natural gas sales activities and station operations continue to lose money, our business will suffer.

We historically have relied on capital contributions by related parties, particularly by Boone Pickens, and such capital may not be available in the future.

              For the fiscal years ended December 31, 2004, 2005 and 2006, Boone Pickens and an affiliated trust made cash investments of $1.9 million, $12.0 million and $18.0 million, respectively, in our company. In August 2006, we entered into a $50 million revolving line of credit with Mr. Pickens to fund margin calls related to our futures contracts. This line of credit was increased to $100 million in November 2006. In December 2006, Mr. Pickens cancelled all amounts we owed to him under this line of credit (approximately $69.7 million) and assumed all of our outstanding futures contracts, together with all associated liabilities and obligations (approximately $78.7 million), in exchange for (1) the issuance to Mr. Pickens of a five-year warrant to purchase up to 15,000,000 shares of our common stock at $10.00 per share (which warrant was valued at $80.9 million), and (2) the assignment to Mr. Pickens of any refunds of margin deposits related to the assumed futures contracts that were made using money borrowed under the line of credit. Additionally, for the fiscal years ended December 31, 2004, 2005 and 2006, Perseus ENRG Expansion, L.L.C. and a related fund invested $3.0 million, $2.0 million and $3.0 million, respectively, in our company. We may not be able to obtain capital from related parties in the future. None of our officers, directors or stockholders (or their respective affiliates) are under any obligation to continue to provide cash to meet our future liquidity needs. If capital is unavailable to us in the future from related parties or from other persons on terms favorable to us, our ability to continue to support our business growth and to respond to business challenges could be significantly limited.

The volatility of natural gas prices could adversely impact the adoption of CNG and LNG vehicle fuel and our business.

              In the recent past, the price of natural gas has been volatile, and this volatility may continue. From the end of 1999 to the end of 2006, the price for natural gas, based on the NYMEX daily futures data, ranged from a low of $1.65 per Mcf to a high of $19.38 per Mcf. As of March 30, 2007, the NYMEX index price for natural gas was $7.50 per Mcf. Increased natural gas prices affect the cost to us of natural gas and will adversely impact our operating margins in cases where we have committed to sell natural gas at a fixed price without a futures contract or with an ineffective

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futures contract that does not fully mitigate the price risk or otherwise cannot pass on the increased costs to our customers. In addition, higher natural gas prices may cause CNG and LNG to cost more than gasoline and diesel generally, which would adversely impact the adoption of CNG and LNG as vehicle fuel. Among the factors that can cause price fluctuations in natural gas prices are changes in domestic and foreign supplies of natural gas, domestic storage levels, crude oil prices, the price difference between crude oil and natural gas, price and availability of alternative fuels, weather conditions, level of consumer demand, economic conditions, price of foreign natural gas imports, and domestic and foreign governmental regulations and political conditions.

The use of natural gas as a vehicle fuel may not become sufficiently accepted for us to expand our business.

              To expand our business, we must develop new fleet customers and obtain and fulfill CNG and LNG fueling contracts from these customers. We cannot guarantee that we will be able to develop these customers or obtain these fueling contracts. Whether we will be able to expand our customer base will depend on a number of factors, including: the level of acceptance and availability of natural gas vehicles, the growth in our target markets of fueling station infrastructure that supports CNG and LNG sales, and our ability to supply CNG and LNG at competitive prices.

The infrastructure to support gasoline and diesel consumption is vastly more developed than the infrastructure for natural gas vehicle fuels.

              Gasoline and diesel fueling stations and service infrastructure are widely available in the United States. For natural gas vehicle fuels to achieve more widespread use in the United States and Canada, they will require a promotional and educational effort, and the development and supply of more natural gas vehicles and fueling stations. This will require significant continued effort by us, as well as government and clean air groups, and we may face resistance from oil companies and other vehicle fuel companies. There is no assurance natural gas will ever achieve the level of acceptance as a vehicle fuel necessary for us to expand our business significantly.

A decline in the demand for vehicular natural gas will reduce our revenue and negatively affect our ability to sustain and grow our operations.

              We derive our revenue primarily from sales of CNG and LNG as a fuel for fleet vehicles, and we expect this trend will continue. A downturn in demand for CNG and LNG would adversely affect our revenue and ability to sustain and grow our operations. Circumstances that could cause a drop in demand for CNG and LNG vehicle fuel are described in other risk factors and include a reduction in supply of natural gas, changes in governmental incentives, the development of other alternative fuels and technologies and a sustained increase in the price of natural gas relative to gasoline and diesel.

If the prices of CNG and LNG do not remain sufficiently below the prices of gasoline and diesel, potential fleet customers will have less incentive to purchase natural gas vehicles or convert their fleets to natural gas, which would decrease demand for CNG and LNG and limit our growth.

              Natural gas vehicles cost more than comparable gasoline or diesel powered vehicles because converting a vehicle to use natural gas adds to its base cost. If the prices of CNG and LNG do not remain sufficiently below the prices of gasoline or diesel, fleet operators may be unable to recover the additional costs of acquiring or converting to natural gas vehicles in a timely manner, and they may choose not to use natural gas vehicles. In that event, our growth would be slowed and our business would suffer.

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Automobile and engine manufacturers produce very few originally manufactured natural gas vehicles and engines for the U.S. and Canadian markets which may restrict our sales.

              Limited availability of natural gas vehicles restricts their wide scale introduction and narrows our potential customer base. Currently, original equipment manufacturers produce a small number of natural gas engines and vehicles, and they may not make adequate investments to expand their natural gas engine and vehicle product lines. For the North American market, there is only one automobile manufacturer that makes natural gas powered passenger vehicles, and manufacturers of medium and heavy-duty vehicles produce only a narrow range and number of natural gas vehicles. Due to the limited supply of natural gas vehicles, our ability to promote natural gas vehicles and our sales may be restricted, even if there is demand.

There are a small number of companies that convert vehicles to operate on natural gas, which may restrict our sales.

              Conversion of vehicle engines from gasoline or diesel to natural gas is performed only by a small number of vehicle conversion suppliers that must meet stringent safety and engine emissions certification standards. The engine certification process is time consuming and expensive and raises vehicle costs. Without an increase in vehicle conversion, vehicle choices for fleet use will remain limited and our sales may be restricted, even if there is demand.

If there are advances in other alternative vehicle fuels or technologies, or if there are improvements in gasoline, diesel or hybrid engines, demand for natural gas vehicles may decline and our business may suffer.

              Technological advances in the production, delivery and use of alternative fuels that are, or are perceived to be, cleaner, more cost-effective or more readily available than CNG or LNG have the potential to slow adoption of natural gas vehicles. Advances in gasoline and diesel engine technology, especially hybrids, may offer a cleaner, cost-effective option and make fleet customers less likely to convert their fleets to natural gas. Technological advances related to ethanol or biodiesel, which are increasingly used as an additive to, or substitute for, gasoline and diesel, may slow the need to diversify fuels and impact the growth of the natural gas vehicle market. In addition, hybrid, electric, hydrogen, and other alternative fuels in experimental or developmental stages may eventually offer a cleaner, more cost-effective alternative to gasoline and diesel than natural gas. Advances in technology which slow the growth of or conversion to natural gas vehicles or which otherwise reduce demand for natural gas as a vehicle fuel will have an adverse effect on our business. Failure of natural gas vehicle technology to advance at a sufficient pace may also limit its adoption and ability to compete with other alternative fuels.

Our ability to supply LNG to new and existing customers is restricted by limited production of LNG and by our ability to source LNG without interruption and near our target markets.

              Production of LNG in the United States is fragmented. LNG is produced at a variety of smaller natural gas plants around the United States as well as at larger plants where it is a byproduct of their primary natural gas production. It may become difficult for us to source additional LNG without interruption and near our current or target markets at competitive prices. If our current LNG liquefaction plant, or any of those from which we purchase LNG, is damaged by severe weather, earthquake or other natural disaster, or otherwise experiences prolonged downtime, our LNG supply will be restricted. In addition, the LNG liquefaction plant we are in the process of building in California may be significantly delayed or never built. If we are unable to supply enough of our own LNG or purchase it from third parties to meet existing customer demand, we may be liable to our customers for penalties. An LNG supply interruption would also limit our ability to expand LNG sales to new customers, which would hinder our growth. Furthermore, because

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transportation of LNG is relatively expensive, if we are required to supply LNG to our customers from distant locations, our operating margins will decrease on those sales.

Our third-party LNG suppliers may cancel their supply contracts with us on short notice or increase LNG prices, which would hinder our ability to meet customer demand and increase our costs.

              Two third-party LNG suppliers supplied approximately 64% of the LNG we sold for the year ended December 31, 2006 and 59% for the first three months ended March 31, 2007. Our contracts with these LNG suppliers generally may be terminated by the supplier on short notice. In particular, our supply agreement with Williams Gas Processing Company, which supplied 47% of our LNG for both the year ended December 31, 2006 and for the first three months ended March 31, 2007, can be terminated by Williams effective June 1, 2007. In addition, under certain circumstances, Williams may significantly increase the price of LNG we purchase upon 24 hours' notice if Williams' costs to produce LNG increases, and we may be required to reimburse Williams for certain other expenses. Our contract with Exxon Mobil Corporation, which supplied 17% of our LNG for the year ended December 31, 2006 and 12% for the first three months ended March 31, 2007, expires July 1, 2007. We may be unable to renew these fueling contracts. Furthermore, there are a limited number of LNG suppliers in or near the areas where our LNG customers are located. It may be difficult to replace an LNG supplier, and we may be unable to obtain alternate suppliers at acceptable prices, in a timely manner or at all. If supply interruptions were to occur, our ability to meet customer demand would be impaired, customers may cancel orders and we may be subject to supply interruption penalties. If we are subject to LNG price increases, our operating margins may be impaired and we may be forced to sell LNG at a loss under our fixed-price LNG supply contracts.

Our growth depends in part on environmental regulations mandating the use of cleaner burning fuels, and modification or repeal of these regulations may adversely impact our business.

              Our business depends in part on environmental regulations in the United States that promote or mandate the use of cleaner burning fuels, including natural gas for vehicles. Industry participants with a vested interest in gasoline and diesel, many of which have substantially greater resources than we do, invest significant time and money in an effort to influence environmental regulations in ways that delay or repeal requirements for cleaner vehicle emissions. The delay, repeal or modification of federal or state policies and regulations that encourage the use of cleaner vehicles could have a detrimental effect on the U.S. natural gas vehicle industry, which, in turn, could slow our growth and adversely affect our business.

Our growth depends in part on tax and related government incentives for clean burning fuels. A reduction in these incentives would increase the cost of natural gas fuel and vehicles for our customers and could significantly reduce our revenue.

              Our business depends in part on tax credits, rebates and similar federal, state and local government incentives that promote the use of natural gas as a vehicle fuel in the United States. The federal excise tax credit of $0.50 per gasoline gallon equivalent of CNG and liquid gallon of LNG sold for vehicle fuel use, which began on October 1, 2006, is scheduled to expire in September 2009. Based on the service relationship we have with our customers, either we or our customers are able to claim the credit. The failure to extend the federal excise tax credit for natural gas, or the repeal of federal or state tax credits for the purchase of natural gas vehicles or natural gas fueling equipment, could have a detrimental effect on the natural gas vehicle industry, which, in turn, could adversely affect our business and results of operations. In addition, if grant funds were no longer available under existing government programs, the purchase of or conversion to natural gas vehicles could slow and our business and results of operations could be adversely affected.

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If we are unable to obtain natural gas in the amounts needed on a timely basis or at reasonable prices, we could experience an interruption of CNG or LNG deliveries or increases in CNG or LNG costs, either of which could have an adverse effect on our business.

              Some regions of the United States and Canada depend heavily on natural gas supplies coming from particular fields or pipelines. Interruptions in field production or in pipeline capacity could reduce the availability of natural gas or possibly create a supply imbalance that increases fuel price. If there are interruptions in field production, pipeline capacity, equipment failure, liquefaction production or delivery, we may experience supply stoppages which could result in our inability to fulfill delivery commitments. This could result in our being liable for contractual damages and daily penalties or otherwise adversely affect our business.

Oil companies and natural gas utilities, which have far greater resources and brand awareness than we have, may expand into the natural gas fuel market, which could harm our business and prospects.

              There are numerous potential competitors who could enter the market for CNG and LNG as vehicle fuels. Many of these potential entrants, such as integrated oil companies and natural gas utilities, have far greater resources and brand awareness than we have. If the use of natural gas vehicles increases, these companies may find it more attractive to enter the market for natural gas vehicle fuels and we may experience increased pricing pressure, reduced operating margins and fewer expansion opportunities.

We are in the process of constructing a new LNG liquefaction plant, which could cost more to build and operate than we estimate and divert resources and management attention.

              We are in the initial stages of designing and constructing an LNG liquefaction plant in California, which we plan to operate upon completion. The construction, implementation and operation of any plant of this nature has inherent risks. Permitting, environmental issues, lack of materials and lack of human resources, among other factors, could delay implementation and start up of the new LNG liquefaction plant and affect the operation of the plant. Building the new facility could also present increased financial exposure through project delays, cost-overruns and incomplete production capability. If the new plant has higher than expected construction or operating costs and is not able to produce expected amounts of LNG, we may be forced to sell LNG at a price below production costs and we may lose money.

If we do not have effective futures contracts in place, increases in natural gas prices may cause us to lose money.

              From 2004 to 2006, we sold and delivered approximately 30 percent of our total gasoline gallon equivalents of CNG and LNG under contracts that provided a fixed price or a price cap to our customers over terms typically ranging from one to three years, and in some cases up to five years. At any given time, however, the market price of natural gas may rise and our obligations to sell fuel under fixed price contracts may be at prices lower than our fuel purchase or production price if we do not have effective futures contracts in place. This circumstance has in the past and may again in the future compel us to sell fuel at a loss, which would adversely affect our results of operations and financial condition. Commencing with the adoption of our revised natural gas hedging policy in February 2007, we expect to purchase futures contracts to hedge our exposure to variability related to substantial fixed price contracts. However, such contracts may not be available or we may not have sufficient financial resources to secure such contacts. In addition, under our hedging policy, we may reduce or remove futures contracts we have in place related to these contracts if such disposition is approved in advance by our board of directors. If we are not economically hedged with respect to our fixed price contracts, we will lose money in connection

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with those contracts during periods in which natural gas prices increase above the prices of natural gas included in our customers' contracts. As of March 31, 2007, we were not economically hedged with respect to any of the anticipated requirements of our fixed price contracts, having sold the related futures contracts which we previously held. Based on natural gas prices as of March 31, 2007, we estimate we will incur between $9.9 million to $12.1 million to cover the increased price of natural gas above the inherent price of natural gas embedded in our customer's fixed price and price cap contracts over the duration of the contracts. See "Management's Discussion and Analysis of Financial Condition and Results of Operations—Critical Accounting Policies—Fixed Price and Price Cap Sales Contracts" on page 37 for more information about these contracts.

Our futures contracts may not be as effective as we intend.

              Our purchase of futures contracts can result in substantial losses under various circumstances, including if we do not accurately estimate the volume requirements under our fixed or price cap customer contracts when determining the volumes included in the futures contracts we purchase. We also could incur significant losses if a counterparty does not perform its obligations under the applicable futures arrangement, the futures arrangement is economically imperfect or ineffective, or our futures policies and procedures are not properly followed or do not work as planned. Furthermore, we cannot assure you that the steps we take to monitor our futures activities will detect and prevent violations of our risk management policies and procedures.

A decline in the value of our futures contracts may result in margin calls that would adversely impact our liquidity.

              We are required to maintain a margin account to cover losses related to our natural gas futures contacts. Futures contracts are valued daily, and if our contracts are in loss positions at the end of a trading day, our broker will transfer the amount of the losses from our margin account to a clearinghouse. If at any time the funds in our margin account drop below a specified maintenance level, our broker will issue a margin call that requires us to restore the balance. Payments we make to satisfy margin calls will reduce our cash reserves, adversely impact our liquidity and may also adversely impact our ability to expand our business. Moreover, if we are unable to satisfy the margin calls related to our futures contracts, our broker may sell these contracts to restore the margin requirement at a substantial loss to us.

Boone Pickens cancelled his guarantee of our futures contracts which will require us to make significantly larger initial margin deposits when we purchase futures contracts. This will adversely affect our cash flows, and we may be unable to secure these contracts on terms that are favorable or affordable to us or at all.

              Historically, we have purchased all of our natural gas futures contracts through Sempra Energy Trading Corp. We did not have any futures contracts outstanding at March 31, 2007. Our past obligations under our contract with Sempra were guaranteed by Boone Pickens. Mr. Pickens is our largest stockholder, a director and the principal of BP Capital, L.P., which advises us regarding our hedging activities. As Mr. Pickens cancelled his guarantee with Sempra as of March 7, 2007, Sempra may cancel our contract with them at any time. Without Mr. Pickens' guarantee, we expect to have significantly larger requirements for upfront margin deposits, on the order of up to ten to fifteen times greater than current deposit requirements. We also anticipate that it will be more difficult to purchase futures contracts generally (i.e., through Sempra or other third parties) without his guarantee. If we cannot enter into futures contracts, our ability to offer fixed price supply contracts to our customers may be impaired and we will become more susceptible to price fluctuations and losses if this were to occur.

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If our futures contracts do not qualify for hedge accounting, our net income and stockholders' equity will fluctuate more significantly from quarter to quarter based on fluctuations in the market value of our futures contracts.

              We account for our futures activities under Statement of Financial Accounting Standards No. 133, which requires us to value our futures contracts at fair market value in our financial statements. Our futures contracts historically have not qualified for hedge accounting, and therefore we have recorded any changes in the fair market value of these contracts directly in our consolidated statements of operations in the line item "derivative (gains) losses" along with any realized gains or losses during the period. In the future, we will attempt to qualify all of our futures contracts for hedge accounting under SFAS No. 133, but there can be no assurances that we will be successful in doing so. To the extent that all or some of our futures contracts do not qualify for hedge accounting, we could incur significant increases and decreases in our net income and stockholders' equity in the future based on fluctuations in the market value of our futures contracts from quarter to quarter. For example, we experienced a derivative gain of $33.1 million for the three months ended September 30, 2005 and experienced derivative losses of $19.9 million, $0.3 million, $65.0 million and $13.7 million for the three months ended December 31, 2005, March 31, 2006, September 30, 2006 and December 31, 2006, respectively. We had no derivative gains or losses for the three months ended June 30, 2006 and March 31, 2007. Please read "Management's Discussion and Analysis of Financial Condition and Results of Operations—Quarterly Results of Operations" on page 46 for more information. Any negative fluctuations may cause our stock price to decline due to our failure to meet or exceed the expectations of securities analysts or investors.

Natural gas operations entail inherent safety and environmental risks that may result in substantial liability to us.

              Natural gas operations entail inherent risks, including equipment defects, malfunctions and failures and natural disasters, which could result in uncontrollable flows of natural gas, fires, explosions and other damages. For example, operation of LNG pumps requires special training and protective equipment because of the extreme low temperatures of LNG. LNG tanker trailers have also in the past been, and may in the future be, involved in accidents that result in explosions, fires and other damage. These risks may expose us to liability for personal injury, wrongful death, property damage, pollution and other environmental damage. We may incur substantial liability and cost if damages are not covered by insurance or are in excess of policy limits.

Our business is heavily concentrated in the western United States, particularly in California and Arizona. Economic downturns in these regions could adversely impact our business.

              Our operations to date have been concentrated in California and Arizona. For the year ended December 31, 2006 and the three months ended March 31, 2007, sales in California accounted for approximately 38% and 40%, respectively and sales in Arizona accounted for approximately 23% and 22%, respectively, of the total amount of gallons we delivered. A decline in the economy in these areas could slow the rate of adoption of natural gas vehicles or impact the availability of incentive funds, both of which could negatively impact our growth.

We provide financing to fleet customers for natural gas vehicles, which exposes our business to credit risks.

              We loan to our customers up to 100% of the purchase price of natural gas vehicles. We may also lease vehicles to customers in the future. There are risks associated with providing financing or leasing that could cause us to lose money. Some of these risks include: most of the equipment financed is vehicles, which are mobile and easily damaged, lost or stolen; there is a risk the borrower may default on payments; we may not be able to bill properly or track payments in

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adequate fashion to sustain growth of this service; and the amount of capital available to us is limited and may not allow us to make loans required by customers.

Our finance and leasing activities may be unsuccessful due to competitive pressures.

              The fleet financing and leasing marketplace is competitive and dominated by large finance companies. These companies may have greater financial resources than we do, offer more attractive rates to customers, finance other types of vehicles and equipment and offer a wider range of financial services to the customer. If these large finance companies do not finance natural gas vehicles and if potential customers prefer to work with these companies, our business may be disadvantaged.

We may incur losses and use working capital if we have to purchase vehicles that we intend to place with customers.

              To ensure availability for our customers, we from time to time enter into binding purchase agreements for natural gas vehicles when there is a production lead time. Although we attempt to arrange for customers to purchase the vehicles before their delivery to us, we may be unable to locate purchasers timely and consequently may need to take delivery of and title to the vehicles. These purchases would adversely affect our cash reserves until such time as we can sell the vehicles to our customers, and we may be forced to sell the vehicles at a loss. At March 31, 2007, we had approximately $6.8 million of vehicles under binding purchase agreements without corresponding customer orders.

If we are unable to attract, retain and motivate our executives and other key personnel our business would be harmed.

              Our ability to manage and expand our business depends significantly on the skills and services of our management team, each of whom may terminate his or her service with us at any time and none of whom are subject to non-compete restrictions. We believe the loss of one or more members of our management team would harm our business because few people have comparable experience working in the natural gas vehicle industry or managing companies similar to ours. Moreover, we intend to grow our operations and to do so will need to hire additional personnel in all areas of our business, particularly in sales and marketing. Competition for qualified personnel is intense, and we therefore may be unable to attract or retain qualified personnel and expand our business as planned.

We rely on related parties for advice regarding our derivative activities, and this advice may not be available to us in the future.

              We depend upon Boone Pickens and his firm, BP Capital, L.P., for advice regarding energy markets and derivative activities. We cannot guarantee that we will be able to retain these services for any period of time. BP Capital may terminate its investment advisory agreement with us at any time upon 30 days written notice to us.

We may have difficulty managing our planned growth.

              If we grow our business as planned, our management team and our operational, financial and accounting systems will also need to be expanded. This expansion would result in increased expenses and may strain our resources. If we are unable to manage this growth, we may experience higher expenses, poor internal controls, employee attrition and customer dissatisfaction, any of which could harm our business. Additionally, we may find it difficult to maintain important

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aspects of our corporate culture, which could negatively affect our ability to retain and recruit personnel, and otherwise adversely affect our future success.

Our business is subject to a variety of governmental regulations that may restrict our business and may result in costs and penalties.

              We are subject to a variety of federal, state and local laws and regulations relating to the environment, health and safety, labor and employment and taxation, among others. These laws and regulations are complex, change frequently and have tended to become more stringent over time. Failure to comply with these laws and regulations may result in a variety of administrative, civil and criminal enforcement measures, including assessment of monetary penalties and the imposition of remedial requirements. From time to time, as part of the regular overall evaluation of our operations, including newly acquired operations, we may be subject to compliance audits by regulatory authorities.

              In connection with our LNG liquefaction activities, we need to apply for facility permits or licenses to address storm water or wastewater discharges, waste handling, and air emissions related to production activities or equipment operations. This may subject us to permitting conditions that may be onerous or costly. Compliance with laws and regulations and enforcement policies by regulatory agencies could require us to make material expenditures.

Risks Related to the Auction Process for this Offering

Potential investors should not expect to sell our shares for a profit shortly after our common stock begins trading.

              A principal factor in determining the initial public offering price for the shares sold in this offering will be the clearing price resulting from an auction conducted by us and our underwriters. The clearing price is the highest price at which all of the shares offered, including the shares subject to the underwriters' over-allotment option, may be sold to potential investors. Although we and our underwriters may elect to set the initial public offering price below the clearing price, the public offering price may be at or near the clearing price. If there is little to no demand for our shares at or above the initial public offering price once trading begins, the price of our shares could decline following our initial public offering. If your objective is to make a short-term profit by selling the shares you purchase in the offering shortly after trading begins, you should not submit a bid in the auction.

Some bids made at or above the initial public offering price may not receive an allocation of shares.

              Our underwriters may require that bidders confirm their bids before the auction for our initial public offering closes. If a bidder is requested to confirm a bid and fails to do so within a required time frame, that bid will be rejected and will not receive an allocation of shares even if the bid is at or above the initial public offering price. Further, if the auction process leads to a pro-rata reduction in allocated shares and a rounding down of share allocations pursuant to the rules of the auction, a bidder may not receive any shares in the offering despite having a bid at or above the initial public offering price range. In addition, we, in consultation with our underwriters, may determine, in our sole discretion, that some bids that are at or above the initial public offering price are manipulative or disruptive to the bidding process or are not creditworthy, or otherwise not in our best interest, in which case such bids will be reduced or rejected. Other conditions for valid bids, including suitability, eligibility and account opening and funding requirements of participating dealers, may vary. As a result of these varying requirements, a bidder may have its participation or bid rejected by one underwriter or participating dealer while another bidder's identical bid is accepted.

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Potential investors may receive a full allocation of the shares they bid for if their bids are successful and should not bid for more shares than they are prepared to purchase.

              If the public offering price is at or near the clearing price for the shares offered in this offering, the number of shares represented by successful bids will equal or nearly equal the number of shares offered by this prospectus. As a result, successful bidders may be allocated all or nearly all of the shares that they bid for in the auction. Therefore, we caution investors against submitting a bid that does not accurately represent the number of shares of our stock they are willing and prepared to purchase.

Risks Related to this Offering and Going Public

If we fail to establish and maintain effective internal controls, our ability to produce accurate financial statements could be impaired, which could adversely affect our operating results, and investors' views of us.

              We will need to strengthen our internal controls over financial reporting in order to ensure that we are able to report financial results accurately and on a timely basis. We have operated as a privately held company and our independent registered public accounting firm has identified certain internal controls over financial reporting that we will need to strengthen so that we can meet our reporting obligations as a public company in a timely and accurate manner. Specifically, we need to automate several of our processes, hire additional personnel with finance and accounting expertise and add additional policies and procedures to bolster our control and disclosure environments. Hiring qualified employees is challenging, and there can be no assurance we will be able to find the people with the skill sets we require in a timely manner. Modifying and changing systems and procedures is also challenging, and there can be no assurance that the systems or procedures will be efficient and effective once they are in place. Our accounting and financial reporting department may not currently have all of the necessary resources to ensure that we will not have significant deficiencies or material weaknesses in our system of internal control over financial reporting. The effectiveness of our internal control over financial reporting may be limited by a variety of factors including: faulty human judgment and errors, omissions or mistakes; inappropriate management override of policies and procedures; and the possibility that any enhancements to disclosure controls and procedures may still not be adequate to assure timely and accurate financial information.

              Ensuring that we have adequate financial and accounting controls to produce accurate financial statements on a timely basis is a costly and time-consuming effort that needs to be re-evaluated frequently. We are beginning the process of documenting, reviewing and improving our internal controls in order to comply with Section 404 of the Sarbanes-Oxley Act of 2002, which requires management assessments of the effectiveness of our internal controls over financial reporting and a report by our independent registered public accounting firm addressing these assessments. Both we and our independent registered public accounting firm will be testing our internal controls in connection with the Section 404 requirements and, as part of that documentation and testing, identify areas for further attention and improvement. Improving our internal controls will likely involve substantial costs and take a significant time to complete, which may distract our officers, directors and employees from the operation of our business. These efforts may not ultimately be effective to maintain adequate internal controls. If we fail to establish and maintain effective controls and procedures for financial reporting, we could be unable to provide timely and accurate financial information. In addition, investor perceptions that our internal controls are inadequate or that we are unable to produce accurate financial statements may negatively affect our stock price.

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We will incur increased costs as a result of being a public company.

              As a public company, we will incur significant legal, accounting and other expenses that we did not incur as a private company. The Sarbanes-Oxley Act, as well as rules subsequently implemented by the SEC, Nasdaq and stock exchanges have required changes in corporate governance practices of public companies. We expect these rules and regulations to increase our legal and financial compliance costs and to make some activities more time-consuming and costly. For example, as a result of becoming a public company, we have created additional board committees and adopted policies regarding internal controls and disclosure. In addition, we will incur additional costs associated with our public company reporting. We also expect these new rules to make it more expensive for us to obtain director and officer liability insurance and we may be required to accept reduced policy limits and coverage.

Our quarterly results of operations have not been predictable in the past and have fluctuated significantly and may not be predictable and may fluctuate in the future.

              Our quarterly results of operations have historically experienced significant fluctuations. Our net losses were $3.0 million, $1.1 million, $41.2 million, $32.2 million and $0.9 million for the three months ended March 31, 2006, June 30, 2006, September 30, 2006, December 31, 2006 and March 31, 2007, respectively. After this offering, our quarterly results may fluctuate significantly as a result of a variety of factors, many of which are beyond our control. If our quarterly results of operations fall below the expectations of securities analysts or investors, the price of our common stock could decline substantially. Fluctuations in our quarterly results of operations historically have primarily been attributable to our derivative gain and losses, but also may be due to a number of other factors, including, but not limited to: our ability to increase sales to existing customers and attract new customers; the addition or loss of large customers; construction cost overruns; the amount and timing of operating costs and capital expenditures related to the maintenance and expansion of our business, operations and infrastructure; changes in the price of natural gas; changes in the prices of CNG and LNG relative to gasoline and diesel; changes in our pricing policies or those of our competitors; the costs related to the acquisition of assets or businesses; regulatory changes; and geopolitical events such as war, threat of war, or terrorist actions. Please read "Management's Discussion and Analysis of Financial Condition and Results of Operations—Quarterly Results of Operations" on page 46.

              Investors in our stock should not rely on the results of one quarter as an indication of future performance as our quarterly revenues and results of operations may vary significantly in the future. Therefore, period-to-period comparisons of our operating results may not be meaningful.

If you purchase shares of our common stock in this offering, you will experience substantial and immediate dilution.

              If you purchase shares of our common stock in this offering, you will experience substantial and immediate dilution of $9.63 per share based on an assumed initial public offering price of $15.00 per share, as the price that you pay will be substantially greater than the net tangible book value per share of the common stock that you acquire. This dilution is due in large part to the fact that our earlier investors paid substantially less than the initial public offering price when they purchased their shares of our stock. You will experience additional dilution upon the exercise of warrants or options to purchase common stock under our equity incentive plans, if we issue restricted stock to our employees under these plans or if we otherwise issue additional shares of our common stock.

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The price of our common stock may be volatile as a result of market conditions unrelated to our company, and the value of your investment could decline.

              The trading price of our common stock following this offering may fluctuate substantially due to factors in the market beyond our control. The price of our common stock that will prevail in the market after this offering may be lower than the price you pay, depending on many factors unrelated to our operating performance. These fluctuations could cause you to lose all or part of your investment in our common stock. Factors that could cause fluctuations in the trading price of our common stock include: price and volume fluctuations in the overall stock market from time to time; actual or anticipated changes or fluctuations in our results of operations; actual or anticipated changes in the expectations of investors or securities analysts; actual or anticipated developments in our competitors' businesses or the competitive landscape generally; litigation involving us or our industry; domestic and international regulatory developments; general economic conditions and trends; widespread adoption of other alternative fuels and technologies; major catastrophic events; or sales of large blocks of our stock.

We cannot assure you that a market will develop for our stock.

              Before this offering, there was no public trading market for our stock, and we cannot assure you that one will develop or be sustained after this offering. If a market does not develop or is not sustained, it may be difficult for you to sell your shares of stock at an attractive price or at all. It is possible that, in future quarters, our operating results may be below the expectations of securities analysts or investors. As a result of these and other factors, the price of our stock may decline, possibly materially.

Sales of outstanding shares of our stock into the market in the future could cause the market price of our stock to drop significantly, even if our business is doing well.

              After this offering, approximately 44,449,555 shares of our common stock will be outstanding. Of these shares, only the 20,000,000 shares of our common stock sold in this offering will be freely tradable, without restriction, in the public market. Additionally, our directors, executive officers and certain principal stockholders have agreed to enter into "lock up" agreements with the underwriters, in which they will agree to refrain from selling their shares for a period of 180 days after this offering. The lock-up is subject to extension under certain circumstances. After the lock-up agreements pertaining to this offering expire, up to an additional 24,449,525 currently outstanding shares will be eligible for sale in the public market, 22,934,159 of which are held by directors, executive officers and other affiliates and will be subject to volume limitations under Rule 144 under the Securities Act of 1933, and various vesting agreements. If our existing stockholders sell, or indicate an intention to sell, substantial amounts of our common stock in the public market after the contractual lock-up and other legal restrictions on resale discussed in this prospectus lapse, the trading price of our common stock could decline. WR Hambrecht + Co may, in its sole discretion, permit our directors, officers, employees and current stockholders who are subject to the 180-day contractual lock-up to sell shares prior to the expiration of the lock-up agreements.

              In addition, as of March 31, 2007, there were 17,401,000 shares underlying options and warrants that were issued and outstanding, and we have authorized grants of options covering 2,825,500 shares of common stock to employees, directors and consultants at the closing of this offering under our 2006 Equity Incentive Plan. These shares will become eligible for sale in the public market to the extent permitted by the provisions of various option and warrant agreements, the lock-up agreements and Rules 144 and 701 under the Securities Act. If these additional shares are sold, or if it is perceived that they will be sold in the public market, the trading price of our stock could decline.

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              Shortly after the effectiveness of this offering, we also intend to file a registration statement on Form S-8 under the Securities Act covering shares of common stock reserved for issuance under our equity incentive plans. Upon filing the Form S-8, shares of common stock issued upon the exercise of options under our equity incentive plans will be available for sale in the public market, subject to Rule 144 volume limitations applicable to affiliates and subject to the lock-up agreements described above.

The warrant for 15,000,000 shares of common stock held by Boone Pickens may have a dilutive effect on the common stock you purchase in this offering.

              In December 2006, we issued to Boone Pickens a warrant to purchase 15,000,000 shares of common stock at an exercise price of $10.00 per share. For more information about the issuance of this warrant, see "Certain Relationships and Related Party Transactions — Obligation Transfer and Securities Purchase Agreement" on page 96. If the value of our common stock exceeds $10.00 per share in the future, this warrant will be dilutive to net income per share of our common stock, which dilution could contribute to a decline in the value of your common stock. Assuming an initial public offering price of $15.00 per share, this warrant will contribute five million shares to the company's fully-diluted shares outstanding calculation.

If securities analysts do not publish research or reports about our business, or if they downgrade our stock, the price of our stock could decline.

              The trading market for our stock will rely in part on the availability of research and reports that third-party industry or financial analysts publish about us. Further, if one or more of the analysts who do cover us downgrade our stock, our stock price may decline. If one or more of these analysts cease coverage of our company, we could lose visibility in the market, which in turn could cause our stock price to decline.

A majority of our stock is beneficially owned by a single stockholder whose interests may differ from yours and who will be able to exert significant influence over our corporate decisions, including a change of control.

              After this offering, Boone Pickens and affiliates (including Madeleine Pickens, his wife) will beneficially own in the aggregate approximately 51.0% of our outstanding common stock, assuming no exercise of the underwriters' over-allotment option, or approximately 48.9%, if the over-allotment option is exercised in full. As a result, Mr. Pickens will be able to influence or control matters requiring approval by our stockholders, including the election of directors and the approval of mergers, acquisitions or other extraordinary transactions. Mr. Pickens may also have interests that differ from yours and may vote in a way with which you disagree and which may be adverse to your interests. This concentration of ownership may have the effect of delaying, preventing or deterring a change of control of our company, could deprive our stockholders of an opportunity to receive a premium for their stock as part of a sale of our company and might ultimately affect the market price of our stock. Conversely, concentration may facilitate a change in control at a time when you and other investors may prefer not to sell.

Provisions in our certificate of incorporation and bylaws and Delaware law may discourage, delay or prevent a change of control of our company or changes in our management and, therefore, depress the trading price of our stock.

              Our certificate of incorporation and bylaws contain provisions that could depress the trading price of our stock by acting to discourage, delay or prevent a change of control of our company or

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changes in our management that the stockholders of our company may deem advantageous. These provisions:

•

authorize the issuance of "blank check" preferred stock that our board of directors could issue to increase the number of outstanding shares to discourage a takeover attempt,



•

provide that a special meeting of stockholders may only be called by our board of directors or our chief executive officer,



•

provide that the board of directors is expressly authorized to make, alter or repeal our bylaws, and



•

establish advance notice requirements for nominations for elections to our board of directors or for proposing matters that can be acted upon by stockholders at stockholder meetings.

              Additionally, we are subject to Section 203 of the Delaware General Corporation Law, which generally prohibits a Delaware corporation from engaging in any of a broad range of business combinations with any "interested" stockholder for a period of three years following the date on which the stockholder became an "interested" stockholder and which may discourage, delay or prevent a change of control of our company.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

              This prospectus contains forward-looking statements. These statements relate to future events or our future financial performance. We have attempted to identify forward-looking statements by terminology such as "anticipate," "believe," "can," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "should," "would" or "will" or the negative of these terms or other comparable terminology. These statements are only predictions and involve known and unknown risks, uncertainties and other factors, including those discussed under "Risk Factors," which could cause our actual results to differ from those projected in any forward-looking statements we make.

              We believe that it is important to communicate our future expectations to our investors. However, there may be events in the future that we are unable to accurately predict or control and that may cause our actual results to differ materially from the expectations we describe in our forward-looking statements. Except as required by law, including U.S. securities laws and rules of the SEC, we do not plan to publicly update or revise any forward-looking statements after we distribute this prospectus, whether as a result of any new information, future events or otherwise. Potential investors should not place undue reliance on our forward-looking statements. Before you invest in our stock, you should be aware that the occurrence of any of the events described in the "Risk Factors" section and elsewhere in this prospectus could harm our business, prospects, operations and financial condition. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements.

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USE OF PROCEEDS

              We estimate that we will receive net proceeds of $137.1 million from our sale of the shares of common stock offered by us in this offering, assuming an initial public offering price of $15.00 per share, the midpoint of the range set forth on the cover page of this prospectus, and after deducting the estimated underwriting discounts and commissions and estimated offering expenses payable by us. We will not receive any of the proceeds from the sale of shares of common stock by the selling stockholders. A $1.00 increase or decrease in the assumed initial public offering price of $15.00 per share would increase or decrease the net proceeds to us from this offering by $9.4 million, assuming no change in the number of shares offered by us as set forth on the cover page of this prospectus.

              We expect to use our proceeds from this offering approximately as follows:

•

$50 to 55 million to build an LNG liquefaction plant in California,



•

$30 to 35 million to build CNG and LNG fueling stations,



•

$15 to 20 million to finance the purchase of natural gas vehicles by our customers, and



•

the balance for general corporate purposes, including making deposits to support our derivative activities, geographic expansion (domestically and perhaps internationally) and to expand our sales and marketing activities.

              We may also use our proceeds from this offering to acquire additional assets or businesses, though no acquisitions are currently pending. We will not receive any of the proceeds from the sale of shares by the selling stockholders.

              Pending the uses described above, we intend to invest the net proceeds from this offering in short-term, interest-bearing, investment-grade securities.

DIVIDEND POLICY

              We currently intend to retain any future earnings to finance the growth, development and expansion of our business and do not anticipate paying cash dividends in the future. Payments of future dividends, if any, will be at the discretion of our board of directors after taking into account various factors, including our business, operating results and financial condition, current and anticipated cash needs, plans for expansion, and any legal or contractual restrictions on the payment of dividends.

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CAPITALIZATION

              The following table sets forth our capitalization as of March 31, 2007:

•

on an actual basis, and



•

on an as adjusted basis to reflect (1) the issuance and sale by us of 10,000,000 shares of our common stock in this offering at an assumed price of $15.00 per share and after deducting underwriting discounts and commissions and estimated offering expenses, and (2) the exercise of options to purchase 256,144 shares of our common stock by selling stockholders in connection with this offering, in each case at an exercise price of $2.96 per share.

              You should read the information below in conjunction with "Management's Discussion and Analysis of Financial Condition and Results of Operations" in this prospectus and our financial statements and the notes thereto in this prospectus.

              A $1.00 increase or decrease in the assumed initial public offering price of $15.00 per share would increase or decrease each of cash and cash equivalents, additional paid-in capital, stockholders' equity and total capitalization by $9.4 million, assuming no change in the number of shares offered by us as set forth on the cover page of this prospectus.

              The table above excludes the following shares:

•

15,000,000 shares of common stock issuable upon the exercise of outstanding warrants held by Boone Pickens at an exercise price of $10.00 per share,



•

2,401,000 shares of common stock issuable upon the exercise of outstanding options at a weighted average exercise price of $2.97 per share (of which options to purchase 2,376,000 shares of our common stock at a weighted average exercise price of $2.96 per share were exercisable), 256,144 of which will be issued upon exercise of such options by selling stockholders in connection with this offering,



•

2,825,500 shares of common stock issuable upon the exercise of options to be granted to employees at the closing of this offering at an exercise price equal to the initial public offering price, and



•

2,187,750 shares of common stock reserved and available for future issuance under our equity incentive plans.

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DILUTION

              If you invest in our common stock, your interest will be diluted to the extent of the difference between the initial public offering price per share of our common stock and the pro forma net tangible book value per share of our common stock immediately after this offering. Net tangible book value per share represents the amount of our total tangible assets less total liabilities, divided by the number of shares of common stock outstanding at March 31, 2007.

              Investors participating in this offering will incur immediate, substantial dilution. The net tangible book value of our common stock as of March 31, 2007 was $101,075,135, or $2.96 per share. Assuming (1) the sale by us of 10,000,000 shares of common stock offered in this offering at an initial public offering price of $15.00 per share, and after deducting estimated underwriting discounts and commissions and estimated offering expenses, and (2) the exercise of options to purchase 256,144 shares of common stock by selling stockholders in connection with this offering at an exercise price of $2.96 per share, our pro forma net tangible book value at March 31, 2007 would have been $238,908,321, or $5.37 per share of common stock. This represents an immediate increase in net tangible book value of $2.41 per share of common stock to our existing stockholders and an immediate dilution of $9.63 per share to the new investors purchasing shares in this offering. The following table illustrates this per share dilution:

              A $1.00 increase or decrease in the assumed initial public offering price of $15.00 per share would increase or decrease our net book value by $9.4 million, the net tangible book value per share, after giving effect to this offering, by $0.21 per share, and the dilution in net tangible book value per share to new investors in this offering by $0.79 per share, assuming no change in the number of shares offered by us as set forth on the cover page of this prospectus.

              The following table sets forth on a pro forma basis, at March 31, 2007, the number of shares of common stock purchased or to be purchased from us, the total consideration paid or to be paid and the average price per share paid or to be paid by existing holders of common stock and by the new investors, before deducting estimated underwriting discounts and estimated offering expenses payable by us.

(1)

Includes 256,144 shares of common stock issued upon exercise of options by selling stockholders in connection with this offering.

              The discussion and tables above are based on the number of shares of common stock outstanding at March 31, 2007.

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              The discussion and tables above (except for the last table above) exclude the following shares:

•

15,000,000 shares of common stock issuable upon the exercise of outstanding warrants held by Boone Pickens at an exercise price of $10.00 per share,



•

2,401,000 shares of common stock issuable upon the exercise of outstanding options at a weighted average exercise price of $2.97 per share (of which options to purchase 2,376,000 shares of our common stock at a weighted average exercise price of $2.96 per share were exercisable), 256,144 of which will be issued upon exercise of such options by selling stockholders in connection with this offering,



•

2,825,500 shares of common stock issuable upon the exercise of options to be granted to employees at the closing of this offering at an exercise price equal to the initial public offering price, and



•

2,187,750 shares of common stock reserved and available for future issuance under our equity incentive plans.

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SELECTED HISTORICAL CONSOLIDATED FINANCIAL DATA

              You should read the following selected historical consolidated financial data in conjunction with "Management's Discussion and Analysis of Financial Condition and Results of Operations" and our financial statements and the notes elsewhere in this prospectus.

              The consolidated statements of operations data for the years ended December 31, 2004, 2005 and 2006, and the consolidated balance sheet data at December 31, 2005 and 2006, are derived from our audited consolidated financial statements in this prospectus. The consolidated statements of operations data for the years ended December 31, 2002 and 2003, and the consolidated balance sheet data at December 31, 2002, 2003 and 2004 are derived from our audited consolidated financial statements that are not included in this prospectus. The consolidated statements of operations data for the three months ended March 31, 2006 and 2007, and the consolidated balance sheet data at March 31, 2006 and 2007, are derived from our unaudited consolidated financial statements included in this prospectus. The unaudited consolidated financial statements include, in the opinion of management, all adjustments that management considers necessary for the fair presentation of the financial information set forth in those statements. The historical results are not necessarily indicative of the results to be expected in any future period.

(1)

Revenue includes the following amounts:

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(2)

2006 amount includes $78,712,599 of losses on derivative contracts. The contracts were assumed by our majority stockholder, Boone Pickens, on December 28, 2006. See "Certain Relationships and Related Party Transactions—Obligation Transfer and Securities Purchase Agreement with Boone Pickens" on page 96.

Adjusted Margin (Non-GAAP)

              A portion of our natural gas fuel sales are covered by contracts under which we are obligated to sell fuel to our customers at a fixed price or a variable price subject to a cap. Our policy is to purchase natural gas futures contracts to cover our estimated fuel sales under these contracts to mitigate the risk that natural gas prices may rise above the natural gas component of the price at which we are obligated to sell gas to our customers. However, from time to time, we have sold these underlying futures contracts when we believed natural gas prices were going to fall. When we sold the futures contracts, we were exposed to the economic risk of rising natural gas prices causing our fixed price or price cap sales contracts to be in a reduced margin position or in a loss position, which occurred from time to time. At December 31, 2006, we had sold all such underlying futures contracts. Effective March 2007, we may no longer sell the underlying futures contracts associated with our fixed-price sales contracts without the prior approval of our board of directors and derivative committee.

              Our management uses a measure called Adjusted Margin to measure our operating performance and manage our business. Adjusted Margin is defined as operating income (loss), plus (1) depreciation and amortization, (2) selling, general and administrative expenses, (3) derivative (gains) losses, and (4) loss on extinguishment of derivative liability, the sum of which is adjusted by a non-GAAP measure which we call "futures contract adjustment," which is described below. Management believes Adjusted Margin provides helpful information for investors about the underlying profitability of our fuel sales activities. Adjusted Margin attempts to approximate the results that would have been reported if our futures contracts would have qualified for hedge accounting under SFAS No. 133 and were held until they matured.

              Futures contract adjustment reflects the gain or loss we would have experienced in a respective period on the underlying futures contracts associated with our fixed price and price cap

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contracts had those underlying contracts been held and allowed to mature according to their contract terms.

              The material limitations of Adjusted Margin are as follows: Adjusted Margin is not a recognized term under GAAP and does not purport to be an alternative to gross margin as an indicator of operating performance or any other GAAP measure. Moreover, because not all companies use identical calculations, this presentation of Adjusted Margin may not be comparable to other similarly-titled measures of other companies. We compensate for these limitations by using Adjusted Margin in conjunction with traditional GAAP operating performance and cash flow measures, and therefore, we do not place undue reliance on this measure.

              The table below shows Adjusted Margin and also reconciles these figures to the GAAP measure operating income (loss):

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MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL
CONDITION AND RESULTS OF OPERATIONS

              This discussion should be read with our financial statements and related notes included elsewhere in this prospectus. In addition to historical information, this discussion includes forward-looking information that involves risks and uncertainties which could cause actual results to differ from management's expectations. Please read "Risk Factors" in this prospectus for a discussion of some of these risks and uncertainties.

              We provide natural gas solutions for vehicle fleets in the United States and Canada. Our primary business activity is supplying CNG and LNG vehicle fuels to our customers. We also build, operate and maintain fueling stations, and help our customers acquire and finance natural gas vehicles and obtain local, state and federal clean air incentives. Our customers include fleet operators in a variety of markets, such as public transit, refuse hauling, airports, taxis and regional trucking.

Overview

              This overview discusses matters on which our management primarily focuses in evaluating our financial condition and operating performance.

              Sources of revenue.    We generate the vast majority of our revenue from supplying CNG and LNG to our customers. The balance of our revenue is provided by operating and maintaining natural gas fueling stations, designing and constructing natural gas fueling stations, and financing our customers' natural gas vehicle purchases.

              Key operating data.    In evaluating our operating performance, our management focuses primarily on (1) the amount of CNG and LNG gasoline gallon equivalents delivered and (2) our revenue, net income (loss), and Adjusted Margin. For more information about Adjusted Margin, please read "Selected Historical Consolidated Financial Data—Adjusted Margin (Non-GAAP)" on page 26. The following table, which you should read in conjunction with our financial statements and notes contained elsewhere in this prospectus, presents our key operating data for the years ended December 31, 2004, 2005 and 2006 and for the three months ended March 31, 2006 and 2007:

              Key trends in 2004, 2005, and 2006.    Vehicle fleet demand for natural gas fuels increased significantly during the years ended December 31, 2004, 2005 and 2006. This growth in demand was attributable primarily to the rising prices of gasoline and diesel relative to CNG and LNG during these periods and increasingly stringent environmental regulations affecting vehicle fleets. For more information on these topics, please read "Business—The Market for Vehicle Fuels" beginning on page 53 and "—Background on Clean Air Regulation" beginning on page 72. We capitalized on this growing demand by securing new fleet customers in a variety of markets, including public

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transit, refuse hauling, airports, taxis and regional trucking. Sales to previously existing customers also increased during these periods as they expanded their fleets.

              The number of fueling stations we served grew from 147 at December 31, 2004 to 172 at March 31, 2007 (a 17.0% increase), and the total annual amount of CNG and LNG gasoline gallon equivalents we delivered increased by 47.7% from 2004 to 2006. The increase in gasoline gallon equivalents delivered, together with higher prices we charged our customers due to higher natural gas prices, contributed to increased revenues during these periods. Our cost of sales also increased during these periods, which was attributable primarily to increased costs related to delivering more CNG and LNG to our customers and the increased price of natural gas.

              Anticipated future trends.    We anticipate that, over the long term, the prices for gasoline and diesel will continue to be higher than the price of natural gas as a vehicle fuel, and more stringent emissions requirements will continue to make traditional gasoline and diesel powered vehicles more expensive for vehicle fleets. We believe there will be significant growth in the consumption of natural gas as a vehicle fuel generally, and our goal is to capitalize on this trend and enhance our leadership position as this market expands. We recently began focusing on the seaports market. We already are building a natural gas fueling station, and plan to build additional natural gas fueling stations that service the Ports of Los Angeles and Long Beach. We also anticipate expanding our sales of CNG and LNG in the other markets in which we operate, including public transit, refuse hauling and airport markets. Consistent with the anticipated growth of our business, we also expect that our operating costs will increase, primarily from the logistics of delivering more CNG and LNG to our customers, as well as from the anticipated expansion of our station network. We also plan to incur significant costs related to the LNG liquefaction plant we are in the initial stages of building in California. Additionally, we intend to increase our sales and marketing team as we seek to expand our existing markets and enter new markets, which will also result in increased costs.

              Sources of liquidity and anticipated capital expenditures.    Our principal sources of liquidity have been cash provided by operations, capital contributions from our stockholders, our cash and cash equivalents and, during the third and fourth quarters of fiscal 2006, a revolving line of credit with Boone Pickens, a director and our largest stockholder. The line of credit was used to fund margin requirements on certain derivative contracts and was terminated in December 2006. We expect to spend our cash primarily on constructing new fueling stations, purchasing new LNG tanker trailers, financing natural gas vehicle purchases by our customers, and for general corporate purposes, including working capital for our expansion. We also are in the initial stages of building an LNG liquefaction plant in California. The cost of building this plant, which we estimate will be approximately $50 to 55 million, would be financed from the proceeds of this offering. For more information, please read "Liquidity and Capital Resources" below.

              Volatility in operating results related to futures contracts.    Historically, we have purchased futures contracts from time to time to help mitigate our exposure to natural gas price fluctuations in current periods and in future periods. Gains and losses related to our futures activities, which appear in the line item derivative (gains) losses, have materially impacted our results of operations in recent periods. For the years ended December 31, 2004, 2005 and 2006 derivative (gains) losses were $(10,572,349), $(44,067,744), and $78,994,947, respectively. For the three month periods ended March 31, 2006 and 2007, derivative (gains) losses were $282,348 and $0, respectively. For this reason and others, we caution investors that our past operating results may not be indicative of future results. For more information, please read "Volatility of Earnings and Cash Flows" and "Risk Management Activities" below.

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              Business risks and uncertainties.    Our business and prospects are exposed to numerous risks and uncertainties. For more information, please read "Risk Factors—Risks Related to Our Business and Industry" beginning on page 7.

History

              In 1996, Boone Pickens and Andrew Littlefair formed Pickens Fuel Corp. to acquire the natural gas fueling businesses of Mesa Petroleum and Southern California Gas Company. In 2001, Clean Energy Fuels Corp. was formed to acquire the combined businesses of Pickens Fuel Corp. and BCG eFuels, Inc., an operator of natural gas fueling stations in Canada. In 2002, we acquired Blue Energy & Technologies, L.L.C., an owner and operator of natural gas fueling station assets previously owned by the Public Service Company of Colorado and the TXU Gas Company. Since that time, through additional acquisitions and investment in fueling stations, we have continued to expand geographically in the United States and Canada.

Operations

              For a general discussion of our operations and the natural gas fueling solutions we offer, please read "Business—Our Solution" on page 60 and "Business—Operations" on page 63.

              We generate revenues principally by selling CNG and LNG to our vehicle fleet customers. For the three months ended March 31, 2007, CNG represented 62% and LNG represented 38% of our natural gas sales (on a gasoline gallon equivalent basis). To a lesser extent, we generate revenues by operating and maintaining natural gas fueling stations that are owned either by us or our customers. Substantially all of our operating and maintenance revenues are generated from CNG stations, as owners of LNG stations tend to operate and maintain their own stations. In addition, we generate a small portion of our revenues by designing and constructing fueling stations and selling or leasing those stations to our customers. Substantially all of our station sale and leasing revenues have been generated from CNG stations. In 2006, we also began providing vehicle finance services to our customers.

CNG Sales

              We sell CNG through fueling stations located on our customers' properties and through our network of public access fueling stations. At these CNG fueling stations, we procure natural gas from local utilities or brokers under standard, floating-rate arrangements and then compress and dispense it into our customers' vehicles. Our CNG sales are made primarily through contracts with our fleet customers. Under these contracts, pricing is determined primarily on an index-plus basis, which is calculated by adding a margin to the local index or utility price for natural gas. We sell a small amount of CNG under fixed-price contracts and also provide price caps to certain customers on their index-plus pricing arrangement. Effective January 1, 2007, we no longer intend to offer price-cap contracts to our customers, but we will continue to perform our obligations under price-cap contracts we entered into before January 1, 2007. Our fleet customers typically are billed monthly based on the volume of CNG sold at a station. A smaller portion of our CNG sales are on a per fill-up basis at prices we set at the pump based on prevailing market conditions. These customers typically pay using a credit card at the station.

LNG Sales

              We sell substantially all of our LNG to fleet customers, who typically own and operate their fueling stations. We also sell a small volume of LNG to customers for non-vehicle use. We procure LNG from third-party producers and also produce LNG at our liquefaction plant in Texas. For LNG that we purchase from third-parties, we typically enter into "take or pay" contracts that require us to purchase minimum volumes of LNG at index-based rates. We deliver LNG via our fleet of 48 tanker trailers to fueling stations, where it is stored and dispensed in liquid form into vehicles. We sell LNG

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principally through supply contracts that are priced on either a fixed-price or index-plus basis. We also provided price caps to certain customers on the index component of their index-plus pricing arrangement for certain contracts we entered into on or prior to December 31, 2006. Effective January 1, 2007, we no longer intend to offer price-cap contracts to our customers, but we will continue to perform our obligations under price-cap contracts we entered into before January 1, 2007. Our LNG contracts provide that we charge our customers periodically based on the volume of LNG supplied.

Government Incentives

              From October 1, 2006 through September 30, 2009, we may receive a Volumetric Excise Tax Credit (VETC) of $0.50 per gasoline gallon equivalent of CNG and $0.50 per liquid gallon of LNG that we sell as vehicle fuel. Based on the service relationship we have with our customers, either we or our customers are able to claim the credit. We expect the tax credit will continue to factor into the price we charge our customers for CNG and LNG in the future. The legislation that created this tax credit also increased the federal excise taxes on sales of CNG from $0.061 to $0.183 per gasoline gallon equivalent and on sales of LNG from $0.119 to $0.243 per LNG gallon. These new excise tax rates are approximately the same as those for gasoline and diesel fuel.

              The Internal Revenue Service has not issued final guidance concerning VETC as it relates to LNG sales to tax-exempt entities. Consequently, we have not recorded any benefit of VETC related to these sales in our financial statements.

Operation and Maintenance

              We generate a smaller portion of our revenue from operation and maintenance agreements for CNG fueling stations where we do not supply the fuel. We refer to this portion of our business as "O&M." At these fueling stations, the customer contracts directly with a local broker or utility to purchase natural gas. For O&M services, we do not sell the fuel itself, but generally charge a per gallon fee based on the volume of fuel dispensed at the station.

Station Construction

              We generate a small portion of our revenue from designing and constructing fueling stations and selling or leasing the stations to our customers. For these projects, we act as general contractor or supervise qualified third-party contractors. We charge construction fees or lease rates based on the size and complexity of the project.

Vehicle Acquisition and Finance

              In 2006, we commenced offering vehicle finance services for some of our customers' purchases of natural gas vehicles or the conversion of their existing gasoline or diesel powered vehicles to operate on natural gas. We loan to our customers up to 100% of the purchase price of their natural gas vehicles. We may also lease vehicles in the future. Where appropriate, we apply for and receive state and federal incentives associated with natural gas vehicle purchases and pass these benefits through to our customers. We may also secure vehicles to place with customers prior to receiving a firm order from our customers, which we may be required to purchase if our customer fails to purchase the vehicle as anticipated. As of March 31, 2007, we have not generated significant revenue from vehicle finance activities.

Key Financial and Operating Data

              Our management uses a variety of financial and operational measures to analyze our performance, the most significant of which are natural gas gallons delivered and Adjusted Margin.

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Natural Gas Gallons Delivered

              We view natural gas gallons delivered as a critical operating measure by which we gauge the performance of our business. We define gallons delivered as CNG and LNG volumes, expressed in gasoline gallon equivalents, that we procure and sell to our customers, plus gasoline gallon equivalents dispensed to customers at stations where we provide O&M services.

Adjusted Margin (Non-GAAP)

              Our management uses a measure called Adjusted Margin to measure our operating performance and manage our business. Adjusted Margin is defined as operating income (loss), plus (1) depreciation and amortization, (2) selling, general and administrative expenses, (3) derivative (gains) losses, and (4) loss on extinguishment of derivative liability, the sum of which is adjusted by a non-GAAP measure which we call "futures contract adjustment," which is described below. Management believes Adjusted Margin provides helpful information for investors about the underlying profitability of our fuel sales activities. Adjusted Margin attempts to approximate the results that would have been reported if our futures contracts would have qualified for hedge accounting under SFAS No. 133 and were held until they matured.

              Futures contract adjustment reflects the gain or loss we would have experienced in a respective period on the underlying futures contracts associated with our fixed price and price cap contracts had those underlying contracts been held and allowed to mature according to their contract terms.

              For more information on Adjusted Margin, please read "Selected Historical Consolidated Financial Data—Adjusted Margin (Non-GAAP)" on page 26.

Volatility of Earnings and Cash Flows

              Our earnings and cash flows historically have fluctuated significantly from period to period based on our futures activities, as our futures contracts to date have not qualified for hedge accounting under SFAS No. 133. See "Critical Accounting Policies—Derivative Activities" below. We have therefore recorded any changes in the fair market value of these contracts directly in our statements of operations in the line item derivative (gains) losses along with any realized gains or losses generated during the period. For example, we experienced derivative gains of $33.1 million for the three months ended September 30, 2005 and experienced derivative losses of $19.9 million, $0.3 million, $65.0 million and $13.7 million for the three months ended December 31, 2005, March 31, 2006, June 30, 2006, September 30, 2006 and December 31, 2006, respectively. We had no derivative gains or losses for the three months ended June 30, 2006 and March 31, 2007. Commencing with the adoption of our revised natural gas hedging policy in February 2007, we plan to structure all subsequent futures contracts as cash flow hedges under SFAS No. 133, but we can not be certain that they will qualify. See "Risk Management Activities" below. If the futures contracts do not qualify for hedge accounting, we could incur significant increases or decreases in our earnings based on fluctuations in the market value of the contracts from period to period.

              Additionally, we are required to maintain a margin account to cover losses related to our natural gas futures contacts. Futures contracts are valued daily, and if our contracts are in loss positions at the end of a trading day, our broker will transfer the amount of the losses from our margin account to a clearinghouse. If at any time the funds in our margin account drop below a specified maintenance level, our broker will issue a margin call that requires us to restore the balance. Consequently, these payments could significantly impact our cash balances.

              The decrease in the value of our futures positions and any required margin deposits on our futures contracts that are in a loss position could significantly impact our financial condition in the future.

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Risk Management Activities

              A significant portion of our natural gas fuel sales are covered by contracts to sell LNG or CNG to our customers at a fixed price or a variable index-based price subject to a cap. These contracts expose us to the risk that the price of natural gas may increase above the natural gas cost component included in the price at which we are committed to sell gas to our customers. We account for sales of natural gas under these contracts as described below in "Critical Accounting Policies—Fixed Price and Price Cap Sales Contracts."

Risk Management Practices Before February 2007

              Historically, when we entered into a contract to sell natural gas fuel to a customer at a fixed price or a variable price subject to a cap, we generally sought to manage our exposure to natural gas price increases for some or all of the expected contract volumes in the natural gas futures market. We did this by purchasing futures contracts that were designed to cover the difference between the commodity portion of the price at which we were committed to sell natural gas and the price we had to pay for gas at delivery, thereby fixing the cost of natural gas we were paying. We generally purchased futures covering all or a portion of our anticipated volumes in future periods.

              From time to time, if we believed natural gas prices would decline in the future, we often elected to terminate futures contracts associated with fixed price or price cap customer contracts by selling the futures contracts and recognizing a gain upon such sales. When we did so, we lost future economic protections provided by the futures contracts.

              From 2003 through 2005, we sold futures contracts covering estimated sales volumes over future periods and realized a net gain of approximately $44.8 million upon the sale of these contracts. In 2006, we disposed of certain futures contracts covering estimated sales volumes over future periods and realized a net loss of $78.7 million. These futures contracts were transferred to and assumed by Boone Pickens in December 2006. For more information about this transfer and assumption, please read "Certain Relationships and Related Party Transactions—Obligation Transfer and Securities Purchase Agreement with Boone Pickens" on page 96.

              Our derivative activities are reflected in the line item derivative (gains) losses in our consolidated statements of operations. Two components make up this line item: (1) realized (gains) losses, and (2) unrealized (gains) losses. Realized (gains) losses represent the actual (gains) losses we realize when we sell or settle a futures contract during a period. Unrealized (gains) losses represent the (gain) or loss we record at the end of each period when we mark to market our open futures contracts at the end of each period. For realized (gains) losses on contracts sold or settled during a period, there is typically a corresponding unrealized loss (gain) on the contracts since the contracts are no longer outstanding at the end of the period and are therefore marked to zero.

              We have a derivative committee of our board of directors and have historically conducted our futures contract activity under the advice of BP Capital L.P. (BP Capital), an entity of which Boone Pickens, our largest stockholder and a director, is the principal. Through December 31, 2006, we paid BP Capital a monthly fee of $10,000 and a commission equal to 20% of our realized gains, net of realized losses, during a calendar year relating to the purchase and sale of natural gas futures contracts. BP Capital remits realized net gains to us, less its applicable commissions, on a monthly basis. We paid fees to BP Capital of $0.4 million in 2004, $11.7 million in 2005, and $2.4 million in 2006. In March 2007, we amended our agreement with BP Capital to remove the 20% commission on our realized gains and losses during a calendar year.

              We historically have purchased our natural gas futures contracts from Sempra Energy Trading Corp. The futures are based on the Henry Hub natural gas price set on the New York Mercantile Exchange. One futures contract for CNG covers approximately 80,000 gasoline gallon

33

equivalents of CNG, and one futures contract for LNG covers approximately 120,000 gallons of LNG. Each contract has historically required a deposit of $1,000, which is below market due to the fact that Boone Pickens had guaranteed our futures obligations to Sempra. Without this guarantee, which was cancelled March 7, 2007, we estimate the deposit amount rate will be approximately $5,000 to $12,000 per contract depending on market conditions. Additionally, without this guaranty, Sempra may terminate our contract. As of December 31, 2006, we had no futures contracts outstanding and no amounts on deposit.

August 2006 Purchase of Futures Contracts and December 2006 Assumption by Boone Pickens

              On August 2, 2006, we purchased the following futures contracts and made related deposits of $9.5 million:

              In December 2006, Mr. Pickens assumed all of these futures contracts, together with any and all associated liabilities and obligations, in exchange for (1) the issuance to Mr. Pickens of a five-year warrant to purchase up to 15,000,000 shares of our common stock at a purchase price of $10.00 per share (which warrant was valued at $80.9 million), and (2) the assignment to Mr. Pickens of any refunds of margin deposits related to the assumed futures contracts that were made using money borrowed under the line of credit. See "Certain Relationships and Related Party Transactions—Obligation Transfer and Securities Purchase Agreement with Boone Pickens" on page 96. At the time of assumption, these futures contracts had lost $78.7 million in value. The difference between the value of the warrant and the value of the losses on the futures contracts ($2.2 million) was recorded in our statement of operations as a loss on extinguishment of derivative liability. This warrant will be dilutive to net income per share if the fair market value of our common stock exceeds $10 per share in the future. Assuming the initial public offering price of $15 per share, this warrant would contribute five million shares to the company's fully-diluted shares outstanding calculation.

Adoption of Revised Natural Gas Hedging Policy in February 2007

              In an effort to mitigate the volatility of our earnings related to our futures contracts and to reduce our risk related to fixed-price sales contracts, our board of directors revisited our risk management policies and procedures and adopted a revised natural gas hedging policy which restricts our ability to purchase natural gas futures contracts and offer fixed-price sales contracts to our customers. Unless otherwise agreed in advance by the board of directors and the derivative committee, we will conduct our futures activities and offer of fixed-price sales contracts pursuant to the policy as follows:

1.

We may purchase futures contracts only to hedge our exposure to variability in expected future cash flows (such variability to be referred to hereafter as Cash Flow Variability) related to fixed-price sales contracts.



2.

We will purchase futures contracts in quantities reasonably expected to hedge effectively our exposure to Cash Flow Variability related to each fixed-price sales contract that we enter into after the date of the policy.

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3.

We may offer a fixed-price sales contract to a customer only if the following three conditions are met:



a.

We purchase futures contracts in quantities reasonably expected to hedge effectively our exposure to Cash Flow Variability related to the fixed-price sales contract;



b.

We reasonably expect we will have funds sufficient: (i) to make the initial margin deposit(s) related to the intended futures contracts; and (ii) to cover estimated margin calls related to these futures contracts; and



c.

For any contract covering 2.5 million or more gasoline gallon equivalents of CNG or LNG per year (or any contract that, combined with previous contracts that year, would cause the total gasoline gallon equivalents contracted for to exceed 7.5 million gasoline gallon equivalents that year), we consult with the derivative committee regarding the proposed transaction, and the derivative committee approves both the offer of the fixed-price sales contract(s) and the purchase of the associated futures contracts.



4.

When we enter into a fixed-price sales contract according to paragraph 3 above, we will purchase sufficient futures contracts to hedge our estimated exposure to the basis differential between: (a) the price of natural gas at the NYMEX Henry Hub delivery point, and (b) the price of natural gas at the customer's delivery point.



5.

If, during the duration of a fixed-price sales contract (including, without limitation, a contract signed before the adoption of this policy, a contract entered into after the adoption of this policy where futures contracts were not originally purchased to hedge the contract, and a contract that subsequently experiences a significant increase in volume that was not originally contemplated when the original futures contracts were purchased to hedge the contract), we do not have associated futures contracts in place that are sufficient to hedge effectively our estimated exposure to Cash Flow Variability related to that fixed-price sales contract, we may purchase futures contracts in quantities reasonably expected to hedge effectively our exposure to Cash Flow Variability related to that fixed-price sales contract, but only if the following two conditions are met:



a.

We reasonably expect we will have funds sufficient: (i) to make the initial margin deposit(s) related to the intended futures contracts; and (ii) to cover estimated margin calls related to these futures contracts; and



b.

For any fixed-price sales contract covering 1.5 million or more gasoline gallon equivalents per year (or any such contract that, combined with previous such contracts that year, would cause the total gasoline equivalents contracted for to exceed 5 million gasoline gallon equivalents that year), we consult with the derivative committee regarding the proposed transaction, and it approves the purchase of the futures contracts.



6.

When we purchase futures contracts in accordance with paragraph 5 above, we may purchase additional futures contracts to hedge our estimated exposure to the basis differential between: (a) the price of natural gas at the NYMEX Henry Hub delivery point, and (b) the price of natural gas at the customer's delivery point.

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7.

We will not sell or otherwise dispose of a futures contract during the duration of the associated fixed-price sales contract.



8.

We will attempt to qualify all futures contracts for hedge accounting as cash flow hedges under SFAS No. 133.

              Due to the restrictions of our revised hedging policy, as well as the rising cost of futures contracts resulting from the loss of Mr. Pickens' guarantee to Sempra, we expect to offer significantly fewer fixed-price sales contracts to our customers. If we do offer a fixed-price sales contract, we anticipate including a price component that would cover our increased costs as well as a return on our estimated cash requirements over the duration of the underlying futures contract. The amount of this price component will vary based on the anticipated volume to be covered under the fixed-price sales contract.

Economic Factors Impacting our Business

              One key economic factor impacting our business is the price differential between the price of crude oil and the price of natural gas. Because the price of crude oil drives the price of gasoline and diesel, as long as the price of crude oil remains proportionately high relative to the price of natural gas, natural gas should enjoy a cost savings as a vehicle fuel when compared to gasoline and diesel. We also believe the price differential between natural gas fuel and diesel will increase in the future as the Ultra Low Sulfur Diesel (ULSD) rules take effect and the processing and refining costs related to ULSD add to its overall cost.

LNG Supply Risk

              One business risk we face is developing the supply of LNG whereby we will have the capacity to expand and grow our business. To address this business risk in the short term, we are in the process of building an LNG liquefaction plant in California. We expect the plant will be scaleable and provide us with up to 90 million additional gallons of LNG per year. We are also assessing other long-term solutions to this issue which may include constructing additional LNG liquefaction plants, attempting to expand the available supply from our existing suppliers, or contracting with new suppliers for the purchase of LNG.

Limited Availability of Natural Gas Vehicles

              Another business risk we face is the limited availability of natural gas vehicles. We are currently working with several vehicle conversion suppliers to expand the offering of natural gas vehicles. As a long term solution, we are attempting to encourage several auto manufacturers to reintroduce previously-produced natural gas vehicles or to expand their vehicle offerings with natural gas engines.

Critical Accounting Policies

              Our discussion and analysis of our financial condition and results of operations is based upon our financial statements, which have been prepared in accordance with U.S. generally accepted accounting principles. The preparation of financial statements requires management to make estimates and judgments that affect the reported amounts of assets and liabilities, revenue and expenses, and disclosures of contingent assets and liabilities as of the date of the financial statements. On a periodic basis, we evaluate our estimates, including those related to revenue recognition, accounts receivable reserves, notes receivable reserves, inventory reserves, asset retirement obligations, derivative values, income taxes, and the market value of equity instruments granted as stock-based compensation. We use historical experience, market quotes, and other assumptions as the basis for making estimates. Actual results could differ from those estimates under different assumptions or conditions. We believe the following critical accounting policies

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affect our more significant judgments and estimates used in the preparation of our financial statements.

Revenue Recognition

              We recognize revenue on our gas sales and for our O&M services in accordance with SEC Staff Accounting Bulletin No. 104, Revenue Recognition, which requires that four basic criteria must be met before revenue can be recognized: (1) persuasive evidence of an arrangement exists; (2) delivery has occurred and title and the risks and rewards of ownership have been transferred to the customer or services have been rendered; (3) the price is fixed or determinable; and (4) collectability is reasonably assured. Applying these factors, we typically recognize revenue from the sale of natural gas at the time fuel is dispensed or, in the case of LNG sales agreements, delivered to the customer's storage facility. We recognize revenue from operation and maintenance agreements as we provide the O&M services.

              In certain transactions with our customers, we agree to provide multiple products or services, including construction of and either leasing or sale of a station, providing operations and maintenance to the station, and sale of fuel to the customer. We evaluate the separability of revenues for deliverables based on the guidance set forth in EITF No. 00-21, which provides a framework for establishing whether or not a particular arrangement with a customer has one or more deliverables. To the extent we have adequate objective evidence of the values of separate deliverable items under a contract, we allocate the revenue from the contract on a relative fair value basis at the inception of the arrangement. If the arrangement contains a lease, we use the existing evidence of fair value to separate the lease from the other deliverables.

              We account for our leasing activities in accordance with SFAS No. 13, Accounting for Leases. Our existing station leases are sales-type leases, giving rise to profit at the delivery of the leased station. Unearned revenue is amortized into income over the life of the lease using the effective interest method. For those arrangements, we recognize gas sales and operations and maintenance service revenues as earned from the customer on a volume-delivered basis.

              We recognize revenue on fueling station construction projects where we sell the station to the customer using the completed contract method in AICPA Statement of Position 81-1, Accounting for Performance of Construction Type and Certain Production Type Contracts.

Derivative Activities

              We account for our derivative instruments, specifically our futures contracts, in accordance with SFAS No. 133, Accounting for Derivative Instruments and Hedging Activities, as amended. SFAS No. 133 requires the recognition of all derivatives as either assets or liabilities in the consolidated balance sheet and the measurement of those instruments at fair value. Our derivatives did not qualify for hedge accounting under SFAS No. 133 for the years ended December 31, 2004, 2005 and 2006. As such, changes in the fair value of the derivatives were recorded directly to our consolidated statements of operations. We determine the fair value of our derivatives at the end of each reporting period based on quoted market prices from the NYMEX.

              We record gains or losses realized on our derivative instruments during the period in the line item derivative (gains) losses in our consolidated statements of operations. We also mark-to-market our open positions at the end of each reporting period with the resulting gain or loss recorded to derivative (gains) losses in our consolidated statements of operations.

Fixed Price and Price Cap Sales Contracts

              Our contracts to sell CNG and LNG at a fixed price or a variable price subject to a cap are, for accounting purposes, firm commitments. Under U.S. generally accepted accounting principles,

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or GAAP, we record the actual results of delivering the fuel under the contract as the sale of the gas occurs. When we enter into these fixed price or price cap contracts with our customers, the price is set based on the prevailing index price of natural gas at that time. However, the index price of natural gas constantly changes, and a difference between the fixed price of the natural gas included in the customer's contract price and the corresponding index price of natural gas typically develops after we enter into the sales contract. If at the time we sell natural gas under the contract the prevailing index price for gas exceeds the commodity portion of our contracted sale price, we incur a loss. During the years ended December 31, 2004 and 2005, the price of natural gas generally increased, and during the year ended December 31, 2006, the price of natural gas generally decreased. During these periods, we entered into several contracts to sell LNG or CNG to customers at a fixed price or an index-based price that is subject to a fixed price cap.

              The following table summarizes important information regarding our fixed price and price cap supply contracts under which we are required to sell fuel to our customers as of March 31, 2007:

(a)

Estimated volumes are in gasoline gallon equivalents for CNG contracts and are in LNG gallons for LNG contracts and represent the volumes we anticipate delivering over to remaining duration of the contracts.

(b)

Average prices are in gasoline gallon equivalents for CNG contracts and are in LNG gallons for LNG contracts. The average prices represent the natural gas commodity component in the customer's contract.

              The price of natural gas has generally increased since we entered into these contracts and fixed or capped the price of CNG or LNG that we sell to the customers. If these contracts had a notional amount as defined under GAAP, then the contracts would be considered derivatives and we would record a loss based on estimated future volumes and the estimated excess of current market prices for natural gas above the cost of the natural gas commodity component of our customer's fixed price or price cap. However, because the contracts have no minimum purchase requirements, they are not considered derivatives and any estimated future losses under these contracts cannot be accrued in our financial statements under GAAP and we recognize the actual results of performing under the contract as the fuel is delivered. If we applied a derivative valuation methodology to these contracts using estimated volumes along with other assumptions, including forward pricing curves and discount rates, we estimate our pre-tax net income would have been lower (higher) by the following ranges for the periods indicated:

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              We estimate we will incur between $9.9 million and $12.1 million to cover the increased price of natural gas above the inherent price of natural gas embedded in our customer's fixed price and price cap contracts over the duration of the contracts. These estimates were based on natural gas futures prices on March 31, 2007, and these estimates may change based on future natural gas prices and may be significantly higher or lower.

              Our volumes under these contracts, in gasoline gallon equivalents, expire as follows:

              These amounts are based on estimates involving a high degree of judgment and actual results may vary materially from these estimates. These amounts have not been recorded in our statements of operations as they are non-GAAP.

Income Taxes

              We compute income taxes under the asset and liability method. This method requires the recognition of deferred tax assets and liabilities for temporary differences between the financial reporting basis and the tax basis of our assets and liabilities. The impact on deferred taxes of changes in tax rates and laws, if any, are applied to the years during which temporary differences are expected to be settled and are reflected in the consolidated financial statements in the period of enactment. We record a valuation allowance against any deferred tax assets when management determines it is more likely than not that the assets will not be realized. When evaluating the need for a valuation analysis, we use estimates involving a high degree of judgment including projected future income and the amounts and estimated timing of the reversal of any deferred tax liabilities.

Stock-Based Compensation

              Effective January 1, 2006, we account for stock options granted using Statement of Financial Accounting Standards No. 123(R) (SFAS No. 123(R)), Share-Based Payment, which has replaced SFAS No. 123 and APB 25. Under SFAS No. 123(R), companies are no longer able to account for share-based compensation transactions using the intrinsic method in accordance with APB 25, but are required to account for such transactions using a fair-value method and recognize the expense in the statements of operations. We adopted the provisions of SFAS No. 123(R) using the prospective transition method. Under the prospective transition method, only new awards, or awards that have been modified, repurchased or cancelled after January 1, 2006 are accounted for using the fair value method.

              We accounted for awards outstanding as of December 31, 2005 using the accounting principles under SFAS No. 123. Under SFAS No. 123, for options granted before January 1, 2006, the fair value of employee stock options was estimated using the Black-Scholes option pricing model, which requires the use of management's judgment in estimating the inputs used to determine fair value. We elected, under the provisions of SFAS No. 123, to account for employee stock-based compensation under APB 25 during the years ended December 31, 2004 and 2005. In the statements of operations, we recorded no compensation expense in 2004 and 2005 because the fair value of the Company's common stock was equal to the exercise price on the date of grant of the options. Therefore, there was no "intrinsic" value to recognize in the statements of

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operations. However, our footnotes disclose the impact on net income in 2004 and 2005 of using the grant date fair value using the Black-Scholes option pricing model.

              As of December 31, 2005, there were no unvested stock options. Therefore, the impact of SFAS No. 123(R) has been reflected in the consolidated statements of operations for share-based awards granted in 2006.

Impairment of Goodwill and Long-lived Assets

              We assess our goodwill for impairment at least annually (or more frequently if there is an indicator of impairment) based on Statement of Financial Accounting Standards No. 142 (SFAS No. 142), Goodwill and Other Intangible Assets. An initial assessment of impairment is made by comparing the fair value of the operations with goodwill, as determined in accordance with SFAS No. 142, to the book value. If the fair value is less than the book value, an impairment is indicated and we must perform a second test to measure the amount of the impairment. In the second test, we calculate the implied fair value of the goodwill by deducting the fair value of all tangible and intangible net assets of the operations with goodwill from the fair value determined in step one of the assessment. If the carrying value of the goodwill exceeds this calculated implied fair value of the goodwill, we will record an impairment charge. We performed our annual tests of goodwill as of December 31, 2004, 2005 and 2006, and there was no impairment indicated.

Recently Issued Accounting Pronouncements

              In December 2004, the Financial Accounting Standards Board (FASB) issued Statement of Financial Accounting Standards No. 123 (revised December 2004), Share-Based Payment (SFAS No. 123(R)). This Statement is a revision of SFAS No. 123. SFAS No. 123(R) establishes standards for the accounting for transactions in which an entity exchanges its equity instruments for goods or services. SFAS No. 123(R) is effective as of the beginning of the first interim period or annual reporting period that begins after June 15, 2005. We did not have any unvested stock options outstanding as of December 31, 2005 that needed to be valued under SFAS No. 123(R). We adopted SFAS No. 123(R) on January 1, 2006 for grants after January 1, 2006.

              In March 2005, the FASB issued FASB Interpretation No. 47, Accounting for Conditional Asset Retirement Obligations (FIN 47), to clarify the term conditional asset retirement obligation as that term is used in FASB Statement No. 143, Accounting for Asset Retirement Obligations. The Interpretation also clarifies when an entity has sufficient information to reasonably estimate the fair value of an asset retirement obligation. FIN 47 was effective for us as of December 31, 2005. The adoption of FIN 47 did not have a material impact on our financial statements.

              In June 2006, the FASB issued FASB Interpretation No. 48, Accounting for Uncertainty in Income Taxes (FIN 48) which prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. The interpretation also provides guidance on derecognition, classification, interest and penalties, accounting in interim periods, disclosure, and transition. FIN 48 is effective for fiscal years beginning after December 15, 2006. We do not expect that the adoption of FIN 48 will have a material impact on our financial statements.

              In June 2006, the FASB ratified its consensus on EITF Issue No. 06-3, How Taxes Collected from Customers and Remitted to Governmental Authorities Should Be Presented in the Income Statement (EITF No. 06-3). The scope of EITF No. 06-3 includes any tax assessed by a governmental authority that is imposed concurrent with or subsequent to a revenue-producing transaction between a seller and a customer and excludes taxes that are assessed on gross receipts or that are an inventoriable cost. For taxes within the scope of this issue that are significant in amount, the consensus requires the following disclosures: (i) the accounting policy elected for

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these taxes and (ii) the amount of the taxes reflected gross in the income statement on an interim and annual basis for all periods presented. The disclosure of those taxes can be done on an aggregate basis. The consensus is effective for interim and annual periods beginning after December 15, 2006. We currently present sales taxes and excise taxes on sales to our customers on a net basis in our financial and we plan to continue to present our excise taxes in this manner subsequent to the adoption of EITF No. 06-3.

              In September 2006, the FASB issued Statement of Financial Accounting Standards No. 157, Fair Value Measurements (SFAS 157), which defines fair value, establishes a framework for measuring fair value in generally accepted accounting principles and expands disclosures about fair value measurements. SFAS 157 is effective for fiscal years beginning after November 15, 2007 and all interim periods within those fiscal years. Earlier application is permitted provided that the reporting entity has not yet issued interim or annual financial statements for that fiscal year. We are currently evaluating the impact, if any, that SFAS 157 may have on our financial statements.

Improvements in Internal Control over Financial Reporting

              We will need to strengthen our internal controls over financial reporting in order to ensure that we can report financial results accurately and on a timely basis. We have operated as a privately held company and our independent registered public accounting firm has identified certain internal controls over financial reporting that we will need to strengthen so that we can meet our reporting obligations as a public company in a timely and accurate manner. Specifically, we need to automate several of our processes, hire additional personnel with finance and accounting expertise and add additional policies and procedures to bolster our control and disclosure environments. Hiring qualified employees is challenging, and there can be no assurance we will be able to find the people with the skill sets we require in a timely manner. Modifying and changing systems and procedures is also challenging, and there can be no assurance that the systems or procedures will be efficient and effective once they are in place.

              As of March 31, 2007, we have completed the implementation of two new billing systems, one for our CNG sales and one for our LNG sales. We have also commenced implementation of a new customer management system that will, among other things, track our station inventory, track our technician's time reporting, prepare and maintain maintenance records on our network of station equipment, and prepare work orders for our technicians based upon manufacturer-recommended maintenance programs. We anticipate completing implementation of this system by June 30, 2007. We plan to implement a new financial reporting package, a fixed asset module for our general ledger system, and a financing package to track our loans to our customers for their vehicle purchases, all of which we anticipate to be implemented by December 31, 2007.

              We are in the process of hiring a manager of financial reporting to help us with our internal and external financial reporting function, including our financial reporting as a public company. We anticipate we will hire someone by June 30, 2007.

              We anticipate undergoing a complete review of our internal control structure in the third and fourth quarter of 2007. Based on this review, we intend to improve our internal controls where we determine they need enhancement. We expect we will have our entire internal control structure, including any new controls we establish, implemented by June of 2008 in anticipation of our compliance with Section 404 of the Sarbanes-Oxley Act of 2002 by December 31, 2008.

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Results of Operations

              The following is a more detailed discussion of our financial condition and results of operations for the periods presented.

Three Months Ended March 31, 2007 Compared to Three Months Ended March 31, 2006

              Revenue.    Revenue increased by $7.1 million to $28.2 million in the three months ended March 31, 2007, from $21.0 million in the three months ended March 31, 2006. This increase was primarily the result of an increase in the number of CNG and LNG gallons delivered from 15.6 million gasoline gallon equivalents in the first three months of 2006 to 17.8 million gasoline gallon equivalents in the first three months of 2007. One of our new transit customers (Long Island Bus, NY) and one of our new airport customers (Los Angeles International Airport shuttle busses) together accounted for 0.9 million gallons of the increase. The remaining increase in gallons delivered was due to the addition of other smaller new customers and growth from our existing customers. We also recorded $3.8 million of revenue related to fuel tax credits that began in October 2006. Revenue also increased between periods due to a $1.8 million increase in station construction revenue between periods. Offsetting these revenue increases was a decrease in the price we charged our customers who pay on an index-plus basis due to decreased natural gas prices between periods. Our effective price per gallon fell to $1.26 per gallon in the three month period ended March 31, 2007, which represents a $0.08 per gallon decrease over the three month period ended March 31, 2006.

              Cost of sales.    Cost of sales increased by $2.2 million to $21.3 million in the three months ended March 31, 2007, from $19.1 million in the three months ended March 31, 2006. This increase was primarily the result of an increase in costs related to delivering more CNG and LNG gallons between periods. Offsetting this increase was a decrease in our effective cost per gallon between periods. Our effective cost per gallon decreased to $1.10 per gallon for the three months ended March 31, 2007, which represents a $0.12 per gallon decrease over the three months ended

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March 31, 2006. Also contributing to the increase in cost of sales between periods is a $1.8 million increase in costs related to construction activities during the three month period ended March 31, 2007.

              Derivative (gains) losses.    Derivative gains increased by $0.3 million to $0.0 million in the three months ended March 31, 2007, from a loss of $0.3 million in the three months ended March 31, 2006. This increase was primarily the result of the fact that we incurred a loss in the three month period ended March 31, 2006 when we liquidated certain futures contracts and we did not purchase or own any futures contracts during the three month period ended March 31, 2007.

              Selling, general and administrative.    Selling general and administrative expenses increased by $1.4 million to $6.3 million in the three months ended March 31, 2007, from $4.9 million in the three months ended March 31, 2006. The increase was primarily related to an increase in salaries and benefits between periods of $0.4 million related to the hiring of additional employees and pay raises provided to our existing employees. Our employee headcount increased from 86 at March 31, 2006 to 102 at March 31, 2007. $0.1 million of the salaries and benefit increase was related to hiring the incremental employees between periods. In addition, our rent expense increased $0.1 million between periods as we acquired additional office space between periods and our travel and entertainment expenses also increased $0.1 million between periods, primarily related to increased travel related to our sales team. Our marketing expenses increased $0.3 million between periods, primarily due to certain advertising we are conducting in the Ports of Los Angeles and Long Beach. Our bad debt expense increased $0.5 million between periods as we provided a reserve against loans made to a vehicle manufacturer during the three months ended March 31, 2007.

              Depreciation and amortization.    Depreciation and amortization increased by $0.4 million to $1.6 million in the three months ended March 31, 2007, from $1.2 million in the three months ended March 31, 2006. This increase was primarily the result of additional depreciation expense in the three months ended March 31, 2007 related to increased property and equipment balances between periods, primarily related to our station network and our fleet of LNG tanker trailers.

              Interest (income) expense, net.    Interest (income) expense, net, increased by $0.1 million from $0.2 million of income in the three months ended March 31, 2006, to $0.3 million of income for the three months ended March 31, 2007. This increase was primarily the result of a decrease in interest expense in the three months ended March 31, 2007 due to the conversion of $4 million of convertible notes in April 2006 which eliminated the interest expense on these notes. Interest income for the three months ended March 31, 2007 was essentially the same as the three months ended March 31, 2006.

              Other expense, net.    Other expense, net increased by $0.1 million from $25,000 of expense in the three months ended March 31, 2006 to $123,000 of expense in the three months ended March 31, 2007. The increase was primarily related to the write-off of certain costs related to a station relocation.

Fiscal Year Ended December 31, 2006 Compared to Fiscal Year Ended December 31, 2005

              Revenue.    Revenue increased by $13.5 million to $91.5 million in the year ended December 31, 2006, from $78.0 million in the year ended December 31, 2005. This increase was primarily the result of an increase in the number of CNG and LNG gallons delivered from 56.8 million gasoline gallon equivalents to 68.4 million gasoline gallon equivalents. Included in our new customers for 2006 were two transit customers (Santa Monica Big Blue Bus and Toronto Transit) and two airport customers (Baltimore/Washington International Airport and the Los Angeles International Airport parking shuttle buses), which in the aggregate accounted for 3.0 million gallons of the increase. The remaining increase in gallons delivered was due to the addition of several

43

other new smaller customers between periods and incremental growth at several of our previously existing customers and stations. 2006 revenue also included $3.8 million of fuel tax credits related to the sale of alternative fuels which began October 1, 2006. Excluding the fuel tax credits we received during the year, our effective price per gallon was consistent between years. The change in our revenues related to the change in our gallons sold between periods was $14.4 million. Offsetting these increases was a $5.0 million decrease in station construction revenues between periods.

              Cost of sales.    Cost of sales increased by $2.0 million to $74.0 million in the year ended December 31, 2006, from $72.0 million in the year ended December 31, 2005. This increase was primarily due to the increased number of CNG and LNG gallons delivered in 2006. This increase was offset by a decrease in the price we paid for natural gas in 2006. Our effective cost per gallon decreased to $1.06 per gallon in 2006, which represents a $.10 per gallon decrease over 2005. Cost of sales also decreased between periods due to a decrease of $5.4 million in station construction costs between periods. For more information regarding natural gas prices in 2006 and 2005, please read "Qualitative and Quantitative Disclosures About Market Risk" on page 50.

              Derivative (gains) losses.    Derivative losses were $79.0 million in the year ended December 31, 2006, as compared to derivative gains of $44.1 million in the year ended December 31, 2005. This decrease was primarily the result of fewer futures contracts sold in 2006 as opposed to 2005 (and at reduced prices), plus a $78.7 million loss incurred in 2006 on certain futures contracts that were transferred to and assumed by our majority stockholder, Boone Pickens, in December 2006. Unrealized losses also increased in 2006 by $7.8 million based on the mark-to-market adjustments of our open positions between periods. We did not have any open futures positions at December 31, 2006.

              Loss on extinguishment of derivative liability.    In December 2006, Boone Pickens, our majority stockholder, assumed all of our outstanding futures contracts, together with any and all associated liabilities and obligations, in exchange for (1) the issuance to Mr. Pickens of a five-year warrant to purchase up to 15,000,000 shares of our common stock at a purchase price of $10.00 per share (which warrant was valued at $80.9 million), and (2) the assignment to Mr. Pickens of any refunds of margin deposits related to the assumed futures contracts that were made using money borrowed under the $100 million line of credit with Mr. Pickens. At the time of assumption, the futures contracts had lost $78.7 million in value. The difference between the value of the warrant and the value of the losses on the futures contracts ($2.2 million) was recorded in our statement of operations for 2006 as a loss on extinguishment of derivative liability. We had no similar expense in 2005.

              Selling, general and administrative.    Selling, general and administrative expenses increased by $3.8 million to $20.9 million in the year ended December 31, 2006, from $17.1 million in the year ended December 31, 2005. This increase was primarily the result of an increase in salaries and benefits between periods of $2.4 million related to the hiring of additional employees and pay raises provided to our existing employees. Our employee count increased from 84 at December 31, 2005 to 97 at December 31, 2006. $275,000 of the salaries and benefits increase was related to increased salaries related to hiring an incremental 13 employees during the year. In addition, our travel and entertainment expenses increased by $372,000 between periods, primarily due to increased travel expenses related to our sales team in 2006. Our legal, accounting and auditing, and software implementation expenses increased by a combined $1.3 million between periods as we implemented several new software packages, including new CNG and LNG billing systems and our new inventory and repair and maintenance tracking system, and we increased our legal and accounting infrastructure in anticipation of becoming a public company. We also spent an additional $200,000 in 2006 on maintenance projects for the Pickens Plant. These increases were offset by a $2.0 million decrease in marketing and policy and promotion expenses between periods.

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              Depreciation and amortization.    Depreciation and amortization increased by $1.9 million to $5.8 million in the year ended December 31, 2006, from $3.9 million in the year ended December 31, 2005. This increase was primarily the result of a full-year's depreciation in 2006 on the assets placed in service in 2005, including the Pickens Plant, and the depreciation on the LNG tanker trailers and station assets placed in service during 2006.

              Interest (income) expense, net.    Interest (income) expense, net increased by $686,000 to $746,000, in the year ended December 31, 2006 from $60,000 in the year ended December 31, 2005. This increase was primarily the result of an increase in interest income during 2006 due to higher average cash balances on hand in 2006 associated with additional capital contributions received in 2006 and the increased interest income earned in 2006 on excess margin deposits made on certain futures contracts. These increases were offset by increased interest expense during 2006 on advances made from a stockholder to fund the excess margin deposits on the associated futures contracts. See "Certain Relationships and Related Party Transactions—Revolving Line of Credit with Boone Pickens" on page 96.

              Other expense, net.    Other expense, net, was $255,000 in the year ended December 31, 2006, as compared to $141,000 in the year ended December 31, 2005. The increase is primarily due to recording the expenses associated with closing six CNG stations in Canada during 2006.

Fiscal Year Ended December 31, 2005 Compared to Fiscal Year Ended December 31, 2004

              Revenue.    Revenue increased by $20.4 million to $78.0 million in the year ended December 31, 2005, from $57.6 million in the year ended December 31, 2004. This increase was primarily the result of an increase in the number of CNG and LNG gallons delivered from 46.3 million gasoline gallon equivalents to 56.8 million gasoline gallon equivalents. Included in our new customers for 2005 were three new transit agencies (Dallas Area Rapid Transit, City of Mesa, and City of Santa Clarita) and two city refuse operators (the City and County of Sacramento) which accounted for 2.7 million gallons of the increase. The remaining increase in gallons delivered was due to the addition of several new customers between periods and incremental growth at several of our previously-existing customers. Revenue also improved because of increased prices we charged our customers who pay on an index-plus basis in 2005 due to rising natural gas prices. Our effective price per gallon rose to $1.24 per gallon in 2005, which represents a $0.17 per gallon increase over 2004.

              Cost of sales.    Cost of sales increased by $23.2 million to $72.0 million in the year ended December 31, 2005, from $48.8 million in the year ended December 31, 2004. This increase was primarily due to the increased number of CNG and LNG gallons delivered and the increased price of natural gas in 2005. Our effective cost per gallon rose to $1.16 per gallon in 2005, which represents a $0.28 per gallon increase over 2004. This cost increase was offset by a $1.7 million reduction in construction costs in 2005 compared to 2004.

              Derivative (gains) losses.    Derivative gains increased by $33.5 million to $44.1 million in the year ended December 31, 2005, from $10.6 million in the year ended December 31, 2004. This increase was primarily the result of selling more futures contracts at significant gains in 2005 as opposed to 2004 due to the increase in natural gas prices that occurred in 2005.

              Selling, general and administrative.    Selling, general and administrative increased by $6.0 million to $17.1 million in the year ended December 31, 2005, from $11.1 million in the year ended December 31, 2004. This increase was primarily the result of an increase in sales and marketing expense and an increase in salaries and benefits related to the hiring of additional employees and pay raises provided to our existing employees. Sales and marketing expense increased $3.4 million and salaries and benefits increased $0.8 million between periods. Our employee count increased from 71 at December 31, 2004 to 84 at December 31, 2005. $0.2 million

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of the salaries and benefits increase was related to increased salaries related to hiring 13 additional employees.

              Depreciation and amortization.    Depreciation and amortization increased by $0.1 million to $3.9 million in the year ended December 31, 2005, from $3.8 million in the year ended December 31, 2004. This increase was primarily the result of the construction of two CNG stations and the purchase of five LNG tanker trailers in 2005, resulting in higher depreciation expense for the year.

              Interest (income) expense, net.    Interest (income) expense, net, decreased by $0.2 million to $60,000 of income in the year ended December 31, 2005, from $97,000 of expense in the year ended December 31, 2004. This increase was primarily the result of an increase in interest income during 2005 due to higher average cash balances on hand in 2005 associated with the sale of futures contracts and additional capital contributions received in 2005. Interest expense for the year ended December 31, 2005 was essentially the same as for the year ended December 31, 2004.

              Other expense, net.    Other expense, net, decreased by $0.5 million to $0.1 million in the year ended December 31, 2005, from $0.6 million in the year ended December 31, 2004. In 2004, we wrote off costs of $0.3 million related to a proposed acquisition that was abandoned during the year.

Quarterly Results of Operations

              The following table sets forth our quarterly consolidated statements of operations data as a percentage of net revenue for the nine quarters ended March 31, 2007. The information for each quarter is unaudited and we have prepared it on the same basis as the audited consolidated financial statements appearing elsewhere in this prospectus. This information includes all adjustments that management considers necessary for the fair presentation of such data. The quarterly data should be read together with our consolidated financial statements and related notes appearing elsewhere in this prospectus. The results of operations for any one quarter are not necessarily indicative of results for any future period.