The hybrid diesel-electric delivery vans are expected to improve UPS fleet fuel economy and decrease vehicle emissions, while maintaining the same reliability and overall performance as conventional vehicles.

NREL’s Fleet Test & Evaluation (FT&E) team is performing a 12-month evaluation of some of the hybrid vans at UPS locations in Dallas and Phoenix. NREL will publish its findings in fall 2008.

Atlanta, Ga.-based UPS hopes the evaluation will speed up market acceptance of hybrid diesel systems.

Freightliner LLC, Portland, Ore., and Workhorse Custom Chassis LLC, Highland Park, Ill., manufactured the hybrid diesel-electric vehicles. The Freightliner model has a Mercedes-Benz MBE 904 four-cylinder diesel engine, while the Workhorse model features an International VT-275 six-cylinder diesel.

Eaton Corp., Cleveland, Ohio, provided the hybrid propulsion systems that employ an Eaton automated transmission, an integrated motor/generator and advanced lithium-ion batteries. The Eaton hybrid system was developed in part under a $7.5 million, 33-month contract from DOE’s Advanced Heavy Hybrid Propulsion System program.

DOE’s Advanced Vehicle Testing Activity (AVTA), part of the department’s FreedomCAR & Vehicle Technologies Program that seeks to develop energy-efficient and environmentally friendly highway transportation technologies, funds the project.