Alternative Fuel Fleet Vehicles

In partnership with industry, NREL evaluates the in-use performance of alternative fuels in delivery, transit, and freight vehicles.

Although biodiesel is the most commonly used alternative fuel in medium- and heavy-duty diesel vehicles, Fischer-Tropsch diesel and liquefied and compressed natural gas are also viable options. NREL also evaluates the performance of hydrogen fuel cell buses.

Renewable Diesel and Biodiesel

Renewable diesel is a conventional petroleum diesel substitute produced from renewable resources. The renewable diesel under study, produced by Solazyme, is an algae-derived drop-in alternative to conventional diesel and does not require any vehicle modifications. Biodiesel is an oxygenated alternative fuel made from vegetable oils, waste cooking oil, or animal fats. Compared to conventional diesel, biodiesel (used in pure form or in blends such as B20) offers reduced particulate matter, carbon monoxide, and hydrocarbon emissions.

Renewable Diesel in United Parcel Service Fleet Vehicles

In partnership with the United Parcel Service and Clean Cities' National Clean Fleets Partnership, NREL compared the fuel economy and emissions impact of renewable diesel versus petroleum diesel in fleet vehicles operated by UPS out of its Houston, Texas, hub. Learn more.

Regional Transportation District Biodiesel Transit Buses

In partnership with the Regional Transportation District in Boulder, Colorado, NREL evaluated the performance of B20 compared to petroleum diesel in transit buses manufactured by Orion with Cummins engines. The results of this evaluation are featured in the 100,000-Mile Evaluation of Transit Buses Operated on Biodiesel Blends report.

St. Louis Metro Biodiesel Transit Buses

In partnership with St. Louis Metro in St. Louis, Missouri, NREL evaluated the performance of B20 compared to ultra-low sulfur diesel in transit buses manufactured by Gillig with Cummins engines. The results of this evaluation are featured in the St. Louis Metro Biodiesel Transit Bus Evaluation report.

U.S. Postal Service Biodiesel Cargo Vans and Trucks

In partnership with the U.S. Postal Service, NREL studied the effects of B20 on the engines and fuel systems of Ford cargo vans and Mack tractor trucks. The results of this study are featured in the Operating Experience and Teardown Analysis for Engines Operated on Biodiesel Blends report.

Fischer-Tropsch Diesel

Also known as a gas-to-liquid fuel, Fischer-Tropsch diesel is created when a gaseous fuel is converted to a liquid and refined to make diesel or gasoline. Fischer-Tropsch diesel offers reduced emissions and is compatible with advanced emission-control devices.

Yosemite Waters Delivery Trucks

In partnership with bottled-water distributor Yosemite Waters in Fullerton, California, NREL evaluated the performance of Fischer-Tropsch diesel in delivery trucks manufactured by International Truck and Engine Corporation. The results of this study are featured in the Final Operability and Chassis Emissions Results from Class 6 Trucks Operating on Gas-to-Liquid Fuel and Catalyzed Diesel Particle Filters report.

Liquefied Natural Gas

Liquefied natural gas (LNG) is a non-toxic, non-corrosive alternative fuel that offers reduced emissions and similar fuel economy compared to conventional fuels.

Norcal Waste Systems LNG Refuse Trucks

In partnership with Norcal Waste Systems in San Francisco, NREL evaluated the performance of LNG trucks equipped with Cummins engines. The results of this study are featured in the Norcal Prototype LNG Truck Fleet: Final Data Report.

Dallas Area Rapid Transit LNG Transit Buses

In partnership with Dallas Area Rapid Transit, NREL studied the performance and operational cost of LNG buses manufactured by NovaBus with Cummins engines compared to conventional diesel buses. The results of this evaluation are featured in the DART LNG Bus Fleet: Final Results report.

Waste Management LNG Refuse Trucks

In partnership with Waste Management, NREL evaluated the performance of LNG trucks manufactured by Mack with E7G engines operating in the Washington, Pennsylvania, area. The results of this study are featured in Waste Management's LNG Truck Fleet Alternative Fuel Truck Evaluation Project: Final Results report.

Compressed Natural Gas

Compressed natural gas (CNG) is a clear, odorless, non-corrosive alternative fuel that offers reduced emissions and similar fuel economy compared to conventional fuel.

United Parcel Service CNG Package Delivery Vehicles

In partnership with the United Parcel Service, NREL evaluated the performance of diesel and CNG package delivery vehicles manufactured by Freightliner with Cummins engines in service in the Hartford, Connecticut, area. The results of this study are featured in the United Parcel Service CNG Truck Fleet: Final Results report.

More Information

For more information about NREL's evaluation of alternative fuel use in fleet vehicles, view additional alternative fuel publications.