Report Shows Progress of Advanced LNG Technology in Heavy-Duty Trucks
August 10, 2004
The U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL) recently released the final report on its evaluation of prototype liquefied natural gas (LNG) waste transfer trucks operated by California's Norcal Waste Systems, Inc. The 12 Class 8 LNG trucks evaluated were equipped with Cummins Westport, Inc., ISXG engines. The ISXG uses the high-pressure direct-injection (HPDI) fuel system, which injects a small amount of diesel into the engine cylinder to provide compression ignition for natural gas fuel.
As part of DOE's Advanced Vehicle Testing Activity, NREL evaluated the prototype trucks over two years of operation and compared them to commercial diesel trucks. The LNG trucks accumulated almost two million miles during the evaluation, with average monthly mileage approaching that of the diesel trucks. The LNG trucks also showed major improvements in fuel economy compared with previous studies of heavy-duty natural gas trucks.
Drivers reported that the performance of the LNG trucks was as good as or better than that of the diesel trucks. For more about the performance, maintenance, and operating costs of the LNG trucks, please read the report, Norcal Prototype LNG Truck Fleet: Final Results (PDF 1.64 MB). DOE, NREL, and California's South Coast Air Quality Management District are exploring further development of the ISXG engine in heavy-duty vehicles.