SecProbe.io

November 2, 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 response dated October 2, 2012  and have the following
additional 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 infor mation you provide in
response to these  comments, we may have  additional comments.

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

Consolidated Financial Statements for the Year Ended December 31, 2011, page 64
Notes to Consolidated Financ ial Statements, page 71

Note 18 Fair Value Measurements, page 103

1. We note your responses to comments 4 and 5 in our letter dated September 20, 2012.  We
acknowledge that the guidance in SAB Topic 14 was specifically written to address
share -based paymen ts with employees or nonemployees in exchange for goods or
services within the scope of ASC 718 or ASC 505 -50.  However, we believe the guidance
on determining volatility included in SAB Topic 14 D, Question 3 , is based on general
finance theory and would generally be consistent with valuation concepts when
estimating volatility for instruments outside the scope of ASC 718.  We note that in the
fifth paragraph of your response to comment 5 you provide the reasons you did not meet

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

 the criteria to exclusively  rely on implied volatility for estimating the fair values of your
common stock options and restricted stock units (RSUs). So that we may better
understand your response and your accounting:

 Please provide us with your analysis of each of  the four criteri a specified in Question
3 of SAB Topic 14 D for your Series I warrants and, based on that analysis, provide
us with your conclusion as to whether these criteria support your exclusive use of
implied volatilities based on your short -term traded options extr apolated over the
remaining term of the warrants for valuing your Series I warrants.

 Your response to comment 5 references the requirement of SAB No. 107 to determine
“the best estimate of expected volatility.”  We note that in valuing your employee
stock options, you determined that the best estimate of expected volatility includes
consideration of both historical and implied volatility.  While we understand that your
warrants are outside the scope of ASC 718, it remains unclear to us why it is
reasonab le that your best estimate of expected volatility under ASC 718 would
consider both historical and implied volatility but your best estimate of expected
volatility for your Series I warrants under general finance theory would solely
consider implied volati lity.  Please tell us in more detail why you believe the inputs
you used to determine the volatility assumptions for the Series I warrants represent
your best estimate of the expected volatility of these instruments.  Also tell us
whether you disagree that  the four criteria specified in Question 3 of SAB Topic 14 D
for the exclusive use of implied volatilities are based on general finance theory and
are considered when valuing instruments outside the scope of ASC 718.  If you
disagree, provide a detailed di scussion of the basis for your disagreement.

 Please tell us the range of expected volatilities you used in determining the fair value
of your Series I warrants at December 31, 2011.

 Please tell us how you determined the volatility assumptions for your employee stock
options and RSUs.  Specifically, please tell us how you determined the weightings
applied to the selected peer group historical volatility, your historical volatility and
implied volatility for your employee stock options and to your histori cal volatility and
implied volatility for your RSUs.  Also, please explain why you believe the
weightings you selected are appropriate.

2. Your response to comment 4 indicates that in the process of establishing the volatility
assumption for your Series I wa rrants , you considered information from an outside
independent valuation specialist, historical volatilities of various periods and an informal
dealer quote from an investment banker who represents the  holders of the Series I
warrants.  Please explain to u s in detail the precise nature of the information you received
from these  additional sources.  Please explain how and why such information was
considered to validate your exclusive use of implied volatility in determining the fair
value of the Series I war rants.

Mr. Andrew J. Littlefair
Clean Energy Fuels Corp.
November 2, 2012
Page 3

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

Sincerely,

 /s/ Jennifer Thompson

Jennifer Thompson
Accounting Branch Chief