Isuzu Motors (Japan) announced Friday that it is
partnering with Canadian company Westport Innovations to develop engines using Westport’s Compressed Natural Gas Direct
Injection (CNG-DI) technology.
Isuzu will put $1.3 million into a one-year project aimed at a 25 percent
improvement in fuel economy over current spark-ignited CNG engines. The CNG-DI technology offers ultra-low emissions
and improved fuel economy.
CNG-DI uses late-cycle high-pressure injection of CNG into the combustion chamber
in a similar fashion to the diesel cycle. Natural gas has a higher ignition temperature than diesel fuel, so a glow plug
is used to achieve ignition. A CNG-DI injector is shown at right.
The Japanese government is supporting the
move to CNG in vehicles as a substitute for diesel engines, in an effort to cut particulate and greenhouse gas
emissions. The government is subsidizing both CNG vehicles and CNG fuel prices that are 54 percent less than gasoline
and up to 38 percent less than diesel on an energy-equivalent basis. There are currently more than 24,000 natural gas
vehicles in Japan.