SecProbe.io

Mail Stop 3561

 October 3, 2006

Andrew J. Littlefair
President and Chief Executive Officer
Clean Energy Fuels Corp.
3020 Old Ranch Parkway, Suite 200
Seal Beach, California  90740

Re: Clean Energy Fuels Corp.
Registration Statement on Form S-1
Filed September 7, 2006
File No. 333-137124

Dear Mr. Littlefair:

We have reviewed your filing and have the following comments.  Where
indicated, we think you should re vise your document in response to these comments.  If
you disagree, we will consider your explanation as to why our comment is inapplicable or
a revision is unnecessary.  Please be as deta iled as necessary in your explanation.  In
some of our comments, we may ask you to provi de us with information so we may better
understand your disclosure.  After reviewing th is information, we may raise additional
comments.
Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our comments or any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.

General
1. We note a number of blank spaces thr oughout your registration statement for
information that you are not entitled to omit pursuant to Rule 430A under the
Securities Act, including the price range and related information based on a bona
fide estimate of the public offering price within that range.  Please allow us
sufficient time to review your complete di sclosure prior to any distribution of
preliminary prospectuses.

Andrew J. Littlefair
Clean Energy Fuels Corp.
October 3, 2006  Page 2
Outside Front Cover Page of Prospectus
2. Please tell us why you believe the text of  the two sections entitled, The Natural
Gas Vehicle Advantage and North America’ s Leader in Clean Transportation, is
appropriate for the beginning of your prospectus or consider relocating them to a section of the prospectus following the risk factors.  The information in these sections appears to be more appropri ate for the body of the document.

Similarly, this comment app lies to the same text and the chart that you have
included in the graphics at the beginning of your prospectus.
3. Please revise the narrative disclosure th at accompanies the artwork so it does not
repeat the disclosure that appears in th e summary.  Please briefly describe the
photographs that you have included.  If you include revenue amounts, please also
include net income figures.

Prospectus Summary, page 1
4. Please review your disclosure and ensure  that you identify the source for the
statements you provide.  Currently, you include many factual statements, but you
have not indicated whether the source of this information is based upon management’s belief, industry data, reports /articles, or any other source.  If the
statements are based upon management’s be lief, please indicate that this is the
case and include an explanation for the basi s of that belief.  Alternatively, if the
information is based upon reports or arti cles, please provide these documents to
us, appropriately marked and dated.  The following are examples only of the
statements for which you need sources:

• “Domestic prices for gasoline and diesel fuel have increased significantly in recent years, largely as a result of higher crude oil prices and constrained domestic refining capacity.  Industry analysts believe that crude oil prices will remain high compared to long-term historical averages as crude oil producers continue to face challenges to find and produce crude oil reserves
in quantities sufficient to  meet growing global demand.”  The Market for
Vehicle Fuel, page 2.

• “Natural gas vehicle fuels have beco me increasingly less expensive than
gasoline and diesel as prices for gasoline and diesel have risen.  In addition, CNG and LNG are also cheaper than the two other most widely available alternative fuels, ethanol blends and biodiesel.”  The Ma rket for Vehicle
Fuels, page 2.

• “We are the leading provider of natural gas as an alternative fuel for vehicle
fleets in the United States and Canada.”  Overview, page 31.

Andrew J. Littlefair
Clean Energy Fuels Corp.
October 3, 2006  Page 3

• “In order to comply with the 2007 standa rds, we expect 2007 and later engine
models to employ significant new emi ssions control technologies…, which
are expect to increase the cost of a diesel vehicle manuf actured in 2006 by as
much as $10,000 to $20,000 per vehicle.”  Emission Reduction, page 54.

• “CNG and LNG are safer than gasoline and diesel because they dissipate into
the air when spilled or in the event of  a vehicle accident.”  Safer, page 56

We may have further comments once we examine your revisions.
5. The summary is intended to provide a br ief overview of the key aspects of your
offering.  Currently, your summary is too long and repeats much of the
information fully discussed in other sec tions of your document, such as in your
Our Business, The Market for Vehicle Fuels, Competitive Strengths, and Business Strategy subsections.  See Instruc tion to Item 503(a) of Regulation S-K.
Please eliminate the Competitive Strengths and Business Strategy subsections and shorten the remaining sections.  Also, you should balance your revenues
disclosure with net income amounts for the same periods.

The Offering, page 5
6. You state that the number of shares of your common stock that will be
outstanding after this offering is based on the number of shar es of capital stock
that was outstanding as of July 31, 2006.  Please estimate the number of shares
of your common stock that will be outsta nding after this offering using a more
recent date than July 31, 2006.

Summary Historical Consolidat ed Financial Data, page 6

Adjusted EBITDA (Non-GAAP), page 7
7. We note your presentation of the non-GAAP  measure “Adjusted EBITDA” here
and throughout the document.  If you c onsider this measure to be a non-GAAP
measure of performance, pleas e indicate this.  Further, please provide cautionary
disclosure that the non-GAAP  measure may not be comparable to similarly titled
measures used by other entities and rem ove any implication that the non-GAAP
measure could be considered an alternative to income (loss) before income taxes,
the most directly comparable GAAP m easure, as an indicator of operating
performance.  Additionally, in arriving at this measure, it appears you exclude
items that are recurring in nature.  Pl ease note that if you present a non-GAAP
performance measure that excludes items of a potentially recurring nature, you should demonstrate the usefulness of the measure.  In this regard, you should
fully address the bullet points in Ques tion 8 of “Frequently Asked Questions

Andrew J. Littlefair
Clean Energy Fuels Corp.
October 3, 2006  Page 4
Regarding the Use of Non-GAAP Financial Measures,” available on our website at
www.sec.gov  in crafting your revised disclosure s.  In this regard, ensure you
revise your disclosures as follows:

• Disclose the specific manner in which you use  the non-GAAP measure to
conduct or evaluate  your business.  If you do not use the measures in any of
the above manners, please explain your basis for presenting the measures as
indicators of performance.

• Discuss the economic substance behind your decision to use the measures.

• Disclose the material limitations asso ciated with use of  the measures as
compared to the use of the most directly comparable GAAP financial measure.

• Disclose the manner in which you comp ensate for these limitations when
using the measures.

• Disclose the substantive reasons wh y you believe the measures provide
useful information to investors.

Risk Factors, page 8
8. Your Risk Factors section should be a discussion of th e most significant factors
that make your offering speculative or ri sky.  You should place risk factors in
context so your readers can understand the specific risk as it applies to you.  See
SEC Release No. 33-7497.  Also, you should no t present risks that are generic or
contain boilerplate language that could a pply to any issuer or  any offering.  We
believe a discussion of risks in generi c terms does not tell your readers how the
risk may affect their investment in you.  Please revise your Risk Factors section
generally to write each risk  factor in plain English a nd avoid using boilerplate or
generic risk factors.  See Item 503(c) of Regulation S-K.  As examples, please
consider the following risk factors:

• “We may encounter environmental, regul atory and other difficulties if we
construct a new LNG plant we have planned, which could increase costs
significantly and divert resources an d management attention.”  Page 14.

• “We may require additional capital to expand our business, and this capital
might not be available on acceptable terms, or at all.”  Page 15.

Andrew J. Littlefair
Clean Energy Fuels Corp.
October 3, 2006  Page 5
• “Changes in financial accounting standa rds or practices may cause adverse,
unexpected financial reporting fluctuations  and affect our reported results of
operations.”  Page 18.

Further, some of your risk factor disc ussions do not clearly and concisely convey
the actual risk, such as the third full ri sk factor on page 17.  Some of your risk
factors should be separated into multiple ri sk factors, such as the first full risk
factor on page 12 and the last risk f actor on page 15.  Also, please consider
whether other subsections or elements of  a discussion within  a subsection are
necessary for this section and whether certain risk factors can be revised or
combined so they are not repetitive.  Accordingly, please thoroughly revise this
section to more precisely articulate the risks to your offering from each risk
factor.  We may have additional comments based upon your revisions.

A decline in the demand for vehicular natural gas will reduce our revenue. . ., page 8
9. In this risk factor, you list seven circ umstances that you claim could cause a drop
in demand for natural vehicle fuel.  Please consider whether any of these
circumstances are risks material enough to be included in their own, separate risk factor.  If not, please cons ider revising this risk fact or so that the factors causing
any drop in demand do not appear more im portant than the overall risk that
demand could drop.

Also, please revise the first risk factor on page 11, the last risk factor on page 14,
and the first full risk factor on page 16 in the same manner.

Our third-party LNG suppliers may cancel th eir supply contracts w ith us on…, page 10
10. You state that you have c ontracts with four LNG suppliers, but you discuss only
two in this risk factor.  Please discu ss your other two LNG suppliers as well.

The volatility of natural gas prices imp acts the cost of us purchasing…, page 11
11. In your Commodity Risk subsection on page 47, you state that over a six year period from the end of 1999 to the end of 2005, the price for natural gas has
ranged from a low of $1.83 per thousand BTU’s to a high of $15.38 per thousand BTU’s.  Please consider including specifica lly this vast price range in this risk
factor or in a sepa rate risk factor.

Our forward contract purchases may result…, page 12
12. Please relocate this risk factor so it appears among the first risk factors given that your net income has fluctuat ed significantly as a result of these forward contract
purchases.

Andrew J. Littlefair
Clean Energy Fuels Corp.
October 3, 2006  Page 6
Management’s Discussion and Analysis of  Financial Condition and Results…, page 31
13. We note from the disclosure on pages 17 and 19 that you are instituting changes to address and improve your internal  control procedures and compliance
capabilities.  In this section, please di scuss the improvements that you must make
to your internal and disclosure controls to the extent that you believe you will have difficulty implementing these changes and that these areas will remain a risk to your financial reporting obligations.
14. Please expand this section to discuss known material trends, demands, commitments, events, or uncertainties th at will have, or are reasonably likely to
have, a material impact on your financ ial condition, operating performance,
revenues, and/or income, or  results in your liquidity decreasing or increasing in
any material way.  Please provide additio nal information about the quality and
variability of your earnings and cash flows so that investors can ascertain the likelihood of the extent past performance is indicative of future performance.
Please discuss whether you expect your fi nancial position to remain at its current
level or to increase or de crease.  Also, you should consider discussing the impact
of any changes on your earnings.  Further,  please discuss in  reasonable detail:

• economic or industry-wide factors relevant to your company, and

• material opportunities, challenges, and risks in the short and long term and
the actions you are taking to address them.

See Item 303 of Regulation S-K and SEC Release No. 33-8350.

Operations, page 31
15. Please revise this subsection to provide a balanced, executive-level discussion of
the most important matters on which you focus in evaluating your financial
condition and operating performance.  Pl ease discuss your mix of CNG and LNG
sales and your operations in managing and maintaining natural gas fueling
stations, designing and constructing fue ling stations, and providing vehicle
finance services.  Consider discussi ng the key operating indicators on which
management focuses in assessing the busin ess.  See Item 303 of Regulation S-K
and SEC Release No. 33-8350.

Critical Accounting Policies, page 35

Derivative Activities, page 36
16. Please revise your disclosure to explain how you determine the fair value of
derivatives at each reporting period.  If quoted market prices are unavailable,

Andrew J. Littlefair
Clean Energy Fuels Corp.
October 3, 2006  Page 7
please explain the significant assumptions a nd estimates used to calculate the fair
value.  Further, provide a sensitivity anal ysis that expresses the potential change
in net income that would result from  hypothetical changes to assumptions and
estimates.  See Section V of SEC Release No. 33-8350.
17. Please explain to us why your derivative  instruments, specifically futures
contracts, do not qualify for hedge accounting under SFAS 133.

Results of Operations, page 39

Six Months Ended June 30, 2006 Compared to  Six Months Ended June 30, 2005, page 39
18. This section explains the types of expenses that are included in each operating expense category.  However, the dollar am ounts mostly repeat information that is
available from the face of the income statement.  Please expand this information to explain the reasons for period-to-period changes.  For example, please discuss
the reason that, as you state in the first paragraph of your Six Months Ended June 30, 2006 Compared to Six Months Ended June 30, 2005 subsection, there was an increase in the number of CNG and LNG gallons delivered from 26.0 million
gallons in 2005 to 32.5 million gallons in 2006.  We note that you account only for 1.6 million gallons of the increase due to your new transit customer.
19. Where you identify intermediate causes of changes in your operating results, ensure you fully describe the reasons underlying such causes.  For example,
stating that your revenue incr ease is attributable, in part , to increases in gasoline
gallons delivered only identifies the inte rmediate cause of the change.  Please
indicate the specific reason or reasons for the volume increase.  Additionally,
please revise your discussion of price and volume increases to indicate the extent
to which price versus volume contributed to the overall change in revenues.  In
this regard, we are unable to