SecProbe.io

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

   Mail Stop 3030

January 29, 2010
Via Facsimile and U.S. Mail

 Mr. Bill Larkin Chief Financial Officer Westport Innovations, Inc. Suite 101, 1750 West 75th Avenue Vancouver, British Columbia, Canada V6P 6G2
Re: Westport Innovations, Inc.
Form 40-F for the Fiscal Year Ended March 31, 2009  Filed June 8, 2009 File No.  001-34152

Dear Mr. Larkin:
We have reviewed your filing and have th e following comments.  Where indicated, we
think you should revise your documents in future filings in response to these comments.  If you
disagree, we will consider your explanation as to why our comments are inapplicable or a revision is unnecessary.  Please be as detailed as necessary in your  explanation.  In some of our
comments, we may ask you to provide us with  information so we may better understand your
disclosure.  After reviewing this information, we may raise additional comments.   Please understand that the purpose of our review process is to  assist you in your compliance
with the applicable disclosure requirements and to enhance the ove rall disclosure in your filing.
We look forward to working with you in thes e 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.

Westport Innovations, Inc.
Mr. Bill Larkin
January 29, 2010 Page 2  Form 40-F for the Fiscal Year Ended March 31, 2009

 Exhibit 92

 Note 24.  Reconciliation to United States Gene rally Accepted Accounting Standards, page F-32

 1. We note on page 10 of this exhibit that you reco rd estimated costs of returns, allowances
and sales incentives.  Please tell us and revise your future filings to explain the nature of
the allowances, sales incentives, and the rights of return that you gi ve to your customers
and how you account for these under U.S. GAAP.  Refer to the guidance in 605-15 and 605-50 of the FASB Accounting Standards Codification.

2. We note from your disclosures on page 7 and pages 24 – 27 of this exhibit and
throughout the filing that you are consolidati ng Cummins Westport, Inc. (CWI), a joint
venture, which you established with Cummins,  Inc.  We further note that you hold a 50%
interest in this joint venture and that you have determined that CWI is a va riable interest
entity whereby you are the primary beneficiary.  As a result of this determination, we
note that you are consolidating this entity for all reporting periods presented.  Please
provide us with your analysis supporti ng your conclusion that  you are the primary
beneficiary of this joint venture under US GAAP.  Refer to  the guidance in 810-10-15 of
the FASB Accounting Standards Codification.

3. We note from page 39 of this exhibit that  you recorded $4.3 million of expenses related
to a change in your warranty estimate.  We further note from pages 9, 15, and 16 of
Exhibit 99.3 that you base your warranty re serves upon historical  failure rates among
other factors and that this change in estimate primarily relates to new products that were
launched in fiscal 2007 and 2009.  Please tell us and revise your future filings to explain
in more detail how you determine your warrant y reserves under US GAAP.  Within your
discussion, please explain in more detail why you base your warranty costs upon
historical failure rates even though a number of your products  are new to the company.
Discuss how you determined that your warranty accruals are sufficient to cover future
warranty claims and clarify each
 of the factors you considered in your analysis.  We may
have further comment based upon reviewing your response.

Exhibit 99.3

-Management’s Discussion and Analysis, page 1

-Disclosure Controls and Procedures and Inte rnal Control Over Fina ncial Reporting, page 13

4. We note from the cover pages of your f iling that you are not required to include
management’s report on the effectiveness of in ternal controls over financial reporting as
of March 31, 2009 since are you are in a tran sition period due to you being a newly
public company.  However, we note here that you concluded your internal controls over

Westport Innovations, Inc.
Mr. Bill Larkin
January 29, 2010 Page 3
financial reporting were ade quately designed as of March 31, 2009 to provide reasonable
assurance regarding the reliability of your fina ncial statement reports.  Please revise your
future filings to include a clear and definite statement as to whether your internal control over financial reporting was effective or not e ffective as of the end of your most recent
fiscal year and to provide all of the disclosures outlined in Section B(6)(c) of the General Instructions to Form 40-F.

-Contractual Obligations and Commitments, page 25

5. Please explain to us how the information provided within this table reconciles to the
information provided within the contractual obligation table included within the cover
pages of your filing.  Within your discussi on, please also explain how the columns
labeled “carrying amount”, “contractual cash fl ows”, “<1 year”, and “2-3 years” total
$6,044, $44,264, $9,868, and $7,889, respectively.

As appropriate, please respond to these comments  within 10 business days or tell us when
you will provide us with a response.  Please furnish a cover letter that keys your responses to our comment and provides any requested information.  Detailed cover letters greatly facilitate our
review.  Please understand that we may have  additional comments after reviewing your
responses to our comments.    We urge all persons who are responsible fo r the accuracy and adequ acy of the disclosure
in the filing to be certain that the filing includes all information re quired under the Securities
Exchange Act of 1934 and that they have provi ded all information investors require for an
informed investment decision.  Since the compa ny and its management are in possession of all
facts relating to a company’s disclosure, they are responsible for the acc uracy and adequacy of
the disclosures they have made.     In connection with responding to our comme nts, please provide, in writing, a statement
from the company acknowledging that:  ‚ the company is responsible for the adequacy and accuracy of the disclo sure in the filing;
‚ staff comments or changes to disclosure in re sponse 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.

In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the sta ff of the Division of Corporati on Finance in our review of your
filing or in response to our comments on your filing.

Westport Innovations, Inc.
Mr. Bill Larkin January 29, 2010 Page 4
 You may contact Tara Harkins, Staff Accountant, at (202) 551-3639 or me at (202) 551-
3616 if you have questions regarding comments on th e financial statements and related matters.
In this regard, do not hesitate to contact me or Kevin Vaughn, Accounting Branch Chief, at (202)
551-3643 with any questions.

       S i n c e r e l y ,

          Lynn Dicker         Reviewing Accountant