~Previously Announced Acquisition Closes on Schedule~

VANCOUVER, July 5, 2011 /PRNewswire/ – Westport Innovations Inc. (TSX:WPT /
NASDAQ:WPRT), a global leader in alternative fuel, low-emissions
transportation technologies, today announced that it has completed the
previously announced purchase of Emer S.p.A. (Emer), of Brescia, Italy,
a leading fuel system provider in the compressed natural gas and
liquefied petroleum gas industry with a significant track record in
technology innovation and operations. After deduction of certain
amounts contractually agreed upon, Westport, at closing, paid
approximately Euro 25.6 million (approximately US$37.2 million), which
consisted of Euro 12.1 million (US$17.6 million) in cash and 881,860
shares of Westport.

The purchase price includes the assumption of approximately Euro 53
million (approximately US$77.0 million) in existing net debt within
Emer. Post-closing, Westport immediately paid down approximately Euro
25 million (US$ 36.3 million) of the debt, leaving approximately Euro
28 million (US$40.7 million) in net debt.

The combined operations, under Westport’s Light-Duty Division, will
offer a complete systems solution to OEMs looking to take advantage of
the growing alternative fuel market. Westport’s Light-Duty Italian
operations, including Emer, will continue to be managed by Maurizio
Grando, Managing Director.

About Westport Innovations Inc.

Westport Innovations Inc. is a global leader in alternative fuel,
low-emissions technologies that allow engines to operate on
clean-burning fuels such as compressed natural gas (CNG), liquefied
natural gas (LNG), hydrogen, and biofuels such as landfill gas. Our
unique technologies reduce nitrogen oxides (NOx), particulate matter
(PM), and greenhouse gas emissions (GHG). The Company focuses on three
distinct categories or target markets – light-, medium-, and heavy-duty
– through Westport business units or joint ventures. Westport’s
Light-Duty Division is focused on light-duty automotive systems,
components and engines, including 2.4L engines for industrial
applications such as forklifts and oilfield service. Cummins Westport
(CWI), a joint venture with Cummins, sells the world’s broadest range
of low-emissions alternative fuel engines for commercial urban fleets
such as buses, refuse trucks and vocational vehicles. Westport Heavy
Duty (Westport HD), our proprietary development platform, is engaged in
the engineering, design and marketing of natural gas-enabling
technology for the heavy-duty diesel engine and truck market. To learn
more about our business, visit our website or subscribe to our RSS feed
at www.westport.com, or follow us on Twitter @WestportWPRT.

Note: This document contains forward-looking statements, including
statements regarding the future management of Westport’s Light-Duty
Italian operations. These statements are neither promises nor
guarantees, but involve known and unknown risks and uncertainties and
are based on assumptions that may cause our actual results, levels of
activity, performance or achievements to be materially different from
any future results, levels of activities, performance or achievements
expressed in or implied by these forward looking statements. These
risks and assumptions include risks and assumptions related to our
future strategy and organization as well as other risk factors and
assumptions that may affect our actual results, performance or
achievements or financial position discussed in our most recent Annual
Information Form and other filings with securities regulators. Readers
should not place undue reliance on any such forward-looking statements,
which speak only as of the date they were made. We disclaim any
obligation to publicly update or revise such statements to reflect any
change in our expectations or in events, conditions or circumstances on
which any such statements may be based, or that may affect the
likelihood that actual results will differ from those set forth in the
forward looking statements except as required by National Instrument
51-102.

SOURCE Westport Innovations Inc.