SecProbe.io

September 20, 2012

Via E -mail
Mr. Andrew J. Littlefair
President and Chief Executive Officer
Clean Energy Fuels Corp.
3020 Old Ranch Parkway, Suite 400
Seal Beach, California  90740

Re: Clean Energy Fuels Corp.
 Form 10-K for Fiscal Year Ended December 31, 2011
Filed March 12, 2012
File No. 001 -33480

Dear Mr. Littlefair :

We have reviewed your filing and have the following comments.  In some of our
comments, we may ask you to provide us with information so we may better understand your
disclosure.

Please respond to this letter within ten business days by amending your filing, by
providing the requested information, or by advising us when you will provide the requested
response .  If you do not believe our comments apply  to your facts and circumstances or do not
believe an amendment is appropriate, please tell us why in your response.

After reviewing any amendment to your filing  and the information you provide in
response to these comments, we may have  additional comments.

Form 10 -K for Fiscal Year Ended December 31, 2011

Selected Financial Data, page 39

1. We note that you have elected to include Stockholders’ Equity in your Selected Financial
Data.  Since your fi nancial statements present Total Stockholders’ Equity as the sum of
your equity accounts including the Noncontrolling Interest in Subsidiary, please use the
same definition of Stockholders’ Equity here to avoid confusion.  Alternatively, if you
believe it is more meaningful to present Total Clean Energy Fuels Corp. Stockholders’
Equity, please revise the title of this line item to clarify the measure that you are
presenting .

Mr. Andrew J. Littlefair
Clean Energy Fuels Corp.
September 20, 2012
Page 2

 Management’s Discussion and Analysis of Financial Condition and Results of Ope rations, page
41

Overview, page 41

2. We note that the amount you presented as your Net Loss in the table at the top of page 42
represents the net loss attributable to Clean Energy Fuels Corp.  Please revise the title of
this line item to clarify the measur e that you are presenting .

Consolidated Financial Statements for the Year Ended December 31, 2011, page 64

Consolidated Statements of Cash Flows, page 70

3. Please explain why contingent consideration paid relating to business acquisitions is
presented in the statement of cash flows as a financing cash flow.

Notes to Consolidated Financial Statements, page 71

Note 18 Fair Value Measurements, page 103

4. We n ote that you believe the best method to approximate the market participant’s view of
the volatility of your Series I warrants has been to use the implied volatilities of your
short -term (i.e. 3 to 9 month) traded options and extrapolate the dat a over the r emaining
term of the Series I warrants, which was approximately 4 years and 4 months as of
December 31, 2011.  Based on your disclosures in this footnote, it appears that this
extrapolated implied volatility is a Level 3 input into your fair value calculat ion under
ASC 820 .  If this is the case, please explain to us why you believe it is appropriate to rely
exclusively on the implied volatility derived from your short -term traded options when
valuing these warrants rather than also considering other Level 3  inputs such as the
historical volatility of the underlying  common stock.

5. In addition, please provide your analysis of  why the differing inputs you used to
determine the expected volatilities of your Series I warrants, employee stock options and
Restrict ed Stock Units produce such differing values for  expected volatilities of these
instruments.  If you believe that these instruments have fundamentally different economic
risks and benefits that justify significantly different methodologies for determining
volatility and significantly different volatilit y outcomes, please explain this in detail.

Item 9A. Controls and Procedures, page 105

6. Please note that you must provide a clear conclusion as to whether any changes occurred
to your internal control over financial reporting during the fourth fiscal quart er that
materially affected, or are reasonably likely to materially affect, your internal control
over financial reporting.   Your current reference to “no other changes” occurring to your

Mr. Andrew J. Littlefair
Clean Energy Fuels Corp.
September 20, 2012
Page 3

 internal controls does not provide a clear conclusion on this matter .  Please confirm to us,
if true, that there were no changes in your internal control over financial reporting that
occurred during the fourth  fiscal quarter that materially affected, or are reasonably likely
to materially affect, your internal control ove r financial reporting.  Alternatively, i f there
were such changes, please revise your disclosure to identify for your investors the
specific changes that materially affected your internal controls .

We urge all persons who are responsible for the accurac y and adequacy of the disclosure
in the filing to be certain that the filing includes the information the Securities Exchange Act of
1934 and all applicable Exchange Act rules require.   Since the company and its management are
in possession of all facts re lating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made.

 In responding to our comments, please provide  a written statement from the company
acknowledging that:

 the company is responsible f or the adequacy and accuracy of the disclosure in the filing;

 staff comments or changes to disclosure in response to staff comments do not foreclose
the Commission from taking any action with respect to the filing; and

 the company may not assert staff comments as a defense in any proceeding initiated by
the Commission or any person under the federal securities laws of the United States.

You may contact  Sondra Snyder, Staff Accountant , at (202) 551 -3332 or me at (202)
551-3737 if you have questions rega rding our comments or any other questions

Sincerely,

 /s/ Jennifer Thompson

Jennifer Thompson
Accounting Branch Chief