National Renewable Energy Laboratory (NREL) - Innovation for Our Energy Future
News Release

Prototype Low-Emissions Natural Gas Engine Saves Fuel


Golden, Colo., April 25, 2002

Using a unique fuel system design, researchers have developed a prototype natural gas engine that significantly improves fuel efficiency without increasing emissions.

A recent report from the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) highlights the promise of the prototype medium-duty natural gas engine equipped with fuel-injected pre-chamber (FIPC) technology. Go to http://www.ctts.nrel.gov/heavy_vehicle/natgas_pub.html#engine for a copy of the full NREL report, "Development of a Throttleless Natural Gas Engine: Final Report," or call the National Alternative Fuels Hotline at 1-800-423-1DOE.

In tests conducted by Southwest Research Institute on behalf of NREL, a John Deere 8.1-liter compressed natural gas (CNG) engine equipped with a specially designed FIPC system showed fuel efficiency gains of as much as 17 percent. Tests showed that emissions of such pollutants as oxides of nitrogen (NOx) and carbon monoxide (CO) compared favorably to those of today's state-of-the-art natural gas engines.

In testing, the prototype engine operated over the full speed and load range, delivering 250 horsepower at 2,200 rpm and 800 lb.-ft. of torque at 1,400 rpm - a torque output similar to that of a diesel engine.

The FIPC engine can operate in throttleless mode across most load levels and in a "leaner" mode than most spark-ignited, open-chamber natural gas engines, meaning it burns less fuel. In tests, the concept engine achieved an impressive 40 percent maximum efficiency at a speed of 1,600 rpm.

The overall performance of the FIPC engine suggests that this design could improve natural gas engines to where they can compete with their diesel counterparts in fuel efficiency while maintaining an emissions advantage.

The report is one of a series issued by NREL to provide information about promising alternative transportation technologies. Most of those reports, plus details on NREL projects and activities in alternative fuels and vehicles are available at www.afdc.nrel.gov.

For more information, please contact NREL Public Affairs at (303) 275-4090 or email public.affairs@nrel.gov

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