Hybrid electric bus

The United States Department of Energy (USDOE) announced the selection of Navistar Corporation for a cost-shared award of up to $10 million to develop, test, and deploy plug-in hybrid electric (PHEV) school buses.

Travel beyond the 40-mile (64 km) range will be facilitated by a clean Diesel engine capable of running on renewable fuels.

The DOE funding will cover up to half of the project's cost and will be provided over three years, subject to annual appropriations.

[12] A report prepared by Purdue University suggests introducing more hybrid Diesel–electric buses and a fuel containing 20% biodiesel (BD20) would further reduce greenhouse emissions and petroleum consumption.

[17] In Japan, Mitsubishi Fuso have developed a diesel engine hybrid bus using lithium batteries in 2002, and this model has since seen limited service in several Japanese cities.

The Wright Pulsar Gemini HEV bus uses a small Diesel engine with electric storage through a lithium ion battery pack.

The use of a 1.9-litre Diesel instead of the typical 7.0-litre engine in a traditional bus demonstrates the possible advantages of serial hybrids in extremely traffic-dense environments.

Based on a London test cycle, a reduction in CO2 emissions of 31% and fuel savings in the range of 40% have been demonstrated, compared with a "Euro-4" compliant bus.