Diesel Hybrids
Hybrid gas-electric vehicles are the current champions of fuel economy, but they may soon get lapped. Auto manufacturers are making tracks to produce diesel hybrids that will go even further on a gallon of fuel.
Hybrid vehicles like the Toyota Prius, Honda Civic Hybrid and Ford Escape Hybrid employ an electric motor that assists the engine and enables the vehicles to go between 15 and 50 percent further on a tank than a comparable gasoline vehicle. But a new generation of hybrid diesel prototypes being developed by General Motors, DaimlerChrysler and Ford could soon surpass these milestones.
Vehicles with diesel engines typically get 25 to 30 percent more miles to the gallon than their gasoline counterparts, according to Charlie Freese, executive engineering director at GM Powertrain. Freese said the many factors that make diesel engines more efficient include operating unthrottled and more efficient oxidizing of fuel. Diesel engines also have a higher compression ratio, and the heavier diesel fuel has a higher energy density, according to Freese.
Source: Wired Magazine, 2005