Paccar Inc. and a small San Diego-based research company developed the prototype vehicle. The California Air Resources Board, which sets the strictest emissions standards in the United States, helped fund the project.
The HEPT vehicle uses a Kenworth T800B chassis, virtually undistinguishable from a regular model from the outside — except when it's running. The big truck operates in near silence, giving off only a slight hum. Test driver Jesse Keller says motorists at stoplights are surprised when the truck suddenly appears in their rear-view mirrors without the usual accompanying diesel rumble. It produces virtually no pollutants and runs on half the energy needed by a typical diesel-powered Class 8 rig.
The diesel engine has been replaced by a 3.8-liter passenger car engine converted to run on natural gas. This runs a generator, which provides power to the electric drive motor and battery packs. The electric engine is 3 feet long, 18 inches wide and weighs about 600 pounds.
The truck has a range of about 250 miles, a limit set by the natural gas capacity. The prototype will enter operational service with a waste-disposal firm in Burbank, CA. A second HEPT prototype will be built in collaboration with Peterbilt, Kenworth's Paccar sister company.
Similar hybrid engine technology is being tested in transit buses around Southern California.
In 1997, CARB donated $350,000 to the project because "it showed the potential to provide an important step in the effort to reduce diesel exhaust's public health threat."
The California Trucking Assn. has mixed feelings about the project. "We're very supportive of alternative fuels," says CTA spokeswoman Stephanie Williams, "but we have some concerns about natural gas because of its explosive nature."
This is only one alternatives being researched with the help of the truck manufacturing industry. DaimlerChrysler, parent company of Freightliner, is testing cars and buses powered by fuel cells, which produce electricity through the chemical reaction of hydrogen and oxygen.