 Most diesel vehicles can use 100% pure biofuels (biodiesel), so they can use but do not need petroleum at all for fuel (although mixes of biofuel and petroleum are more common).If diesel-electric HEVs were in use, this benefit would likely also apply.Diesel-electric hybrid drivetrains have begun to appear in commercial vehicles (particularly buses); , no light duty diesel-electric hybrid passenger cars are available, although prototypes exist.