Westport Innovations said it is accelerating the testing of its natural gas fuel system technology for a new Isuzu diesel engine for light-duty trucks. Vancouver, British Columbia-based Westport has agreed to install its prototype natural gas fuel system in two of the engines for testing by Isuzu in Japan. Isuzu in return has agreed to offset some of Westport's research and development expenses. Westport president & CEO David Demers said the testing has been sped up to help the two companies decide whether to move into commercial production a natural-gas powered truck. Westport will continue testing its fuel system in one Isuzu diesel engine in Vancouver as planned under the original agreement. The tests are set to wrap up on June 30.