Westport Innovations Receives California Air Resources Board 'CARB' Certification of Heavy Duty LNG Truck Engine

VANCOUVER, British Columbia--March 30, 2006--Westport Innovations Inc. (TSX:WPT) -

Westport Heavy Duty HPDI Available for Commercial Deployment

Westport Innovations Inc. a global leader in gaseous-fuelled power technologies, has received California Air Resources Board (CARB) Certification for its High Pressure Direct Injection (HPDI) technology adapted to the Cummins ISX heavy-duty truck engine. The Executive Order from CARB certifies the HPDI system to 1.2g/bhp-hr (NOx + nmHC) and 0.02g/bhp-hr Particulate Matter (PM).

"CARB certification represents the major milestone required for us to make the heavy duty Cummins ISX HPDI LNG (liquefied natural gas) engine and fuel system available to commercial fleets in California for deployment in 2006," stated Michael Gallagher, President & Chief Operating Officer of Westport. "With almost 6 million miles of on-road experience, our own extensive development and engine testing in partnership with Cummins, and the hard work of our dedicated supply chain partners, we are confident the ISX HPDI will become the benchmark for performance in clean heavy duty LNG engines."

About the Heavy Duty Cummins ISX HPDI Natural Gas Engine

The Cummins ISX diesel engine has demonstrated industry-leading performance and reliability and is the market leader in its class. Cummins has been the market leader in diesel engines for Class 8 trucks in North America for the past 27 years. Westport began development of the HPDI version of the ISX engine in co-operation with Cummins in 2000.

Westport's HPDI system enables the industry-leading Cummins ISX engine to operate on natural gas. The ISX HPDI engine will be offered in two ratings, 400 horsepower with 1450ft-lbs torque, or 450 horsepower with 1650 ft-lbs torque, matching the diesel-fueled base ISX engine. The ISX HPDI will be offered to selected truck purchasers with the appropriate Cummins 2004 to 2006 model year diesel ISX engines.

John Wall, Vice President, Chief Technical Officer of Cummins Inc., stated, "This latest step by Westport, with their unique LNG fuel system and proprietary injector technology, continues to demonstrate the capability of HPDI direct gas injection technology to deliver diesel-like performance and efficiency with natural gas."

Available for 2006 delivery, Westport expects that most customers will choose to package the HPDI ISX engine, LNG fuel supply system and new vehicles at the same time. Westport is establishing partnerships to coordinate all aspects of the introduction of LNG fueling for commercial fleets in California. One such partnership is with Clean Energy Fuels, Inc. of Seal Beach, California, for the supply of LNG fuel to fleets. Clean Energy is now the largest provider of natural gas for transportation in North America, with a broad customer base in the refuse, transit, shuttle, taxi, police, intrastate and interstate trucking, airport and municipal fleets.

"We are working vigorously to support LNG as a fuel for heavy-duty vehicle fleet customers and intend to grow the availability of LNG in California significantly," said Andrew J. Littlefair, President of Clean Energy. "We can offer complete packaged fuelling solutions for fleet customers, including construction and maintenance of LNG refuelling stations, supply of fuel, and long-term, fixed-price guarantees for LNG fuel contracts."

Economics for HPDI trucks fueled with LNG are becoming increasingly favourable. New national tax credits across the United States, added to incentive programs from state agencies and the natural gas industry, offer fleets the opportunity to become environmental leaders cost effectively.

The South Coast Air Quality Management District (SCAQMD), the air pollution control agency for the urban portions of Los Angeles, Riverside and San Bernardino Counties, is also a supporter of LNG Class 8 trucks in the Los Angeles basin. "A disproportionate amount of our region's air pollution comes from heavy-duty vehicles," said Dr. Barry Wallerstein, SCAQMD's Executive Officer. "A significant number of trucks operating out of the two largest marine ports in the United States are older trucks. We strongly support all clean fuel technologies. We have supported the development and deployment of Westport's HPDI LNG technology because it enables us to achieve three key objectives: reduce smog-forming oxides of nitrogen (NOx), particulate matter (PM) emissions, and lessen our reliance on petroleum in this high-fuel use transportation sector."

HPDI Customer Experiences

Early prototype versions of the HPDI system have been in daily use with Norcal Waste Systems in San Francisco since August 2001. This initial field trial has accumulated almost 5.5 million miles of operation in waste transfer applications. Westport will deliver 3 of its new CARB- certified systems to Norcal for operation in April 2006, as part of an agreement to extend the use of the HPDI LNG truck fleet until 2011.

In May, 2005 a second-generation on-road trial began along the busy Highway 401 Corridor in southwestern Ontario, Canada with the support of Sustainable Development Technology Canada, Natural Resources Canada, Transport Canada and Enbridge Gas Distribution Inc. The Clean Air Corridor program deployed 5 HPDI LNG trucks hauling up to 140,000lbs GVW. The HPDI trucks are operated by Challenger Motor Freight and replaced conventional diesel trucks on two different routes. A mid-term report on this program has been published and is now available on Westport's website, www.westport.com. The report summarizes:

- Average monthly utilization in excess of 12,000 kms/vehicle for total mileage to date of over 335,000 km

- High truck availability of 99% in the period from August to October

- Average fuel economy comparable to diesel baseline (within 3% including measurement error)

- High driver satisfaction regarding performance and operating characteristics

About High Pressure Direct Injection (HPDI)

HPDI allows a diesel engine to operate with over 90% replacement of diesel fuel by natural gas. By directly injecting the natural gas at high pressure in the engine, HPDI reproduces key benefits of diesel engines: high efficiency over the speed and torque operating range, high torque capability and robust reliability. The use of pilot diesel provides powerful ignition and contributes to the reliability and durability of the system. At the same time, the properties of natural gas contribute to a significant reduction in combustion by-products: nitrogen oxides, particulate matter and greenhouse gases are all significantly reduced as the engine operates under the same performance as the base diesel engine.

Westport acknowledges the support of many industry and government partners during the development of the HPDI technology, including Cummins, SCAQMD, the US Department of Energy's National Renewable Energy Laboratory, Natural Resources Canada, Technology Partnerships Canada and Sustainable Development Technology Canada. In addition, Westport was founded with technology from the University of British Columbia, where basic research supporting HPDI continues to be done.

About Westport Innovations Inc.

Westport Innovations Inc. is the leading developer of environmental technologies that allow engines to operate on clean-burning fuels such as natural gas, hydrogen, and hydrogen-enriched natural gas (HCNG). Westport has technology development alliances in place with Cummins, Ford, MAN, BMW, and Isuzu, as well as an ownership interest in Clean Energy, the largest provider of natural gas for vehicles in North America. Cummins Westport Inc., Westport's joint venture with Cummins Inc., manufactures and sells the world's widest range of low-emissions alternative fuel engines for commercial transportation applications such as trucks and buses.

Note: This document contains forward-looking statements about Westport's business, operations, technology development or the environment in which it operates, which are based on Westport's estimates, forecasts and projections. These statements are not guarantees of future performance and involve risks and uncertainties that are difficult to predict, or are beyond Westport's control. Consequently, readers should not place any undue reliance on such forward-looking statements. In addition, these forward-looking statements relate to the date on which they are made. Westport disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

The Toronto Stock Exchange has not reviewed and does not accept re sponsibility for the adequacy or accuracy of this release.

Westport Innovations Inc. (TSX:WPT)