Audi A8 Hybrid

The hybrid system can drive the A8 under electric power at up to 40 mph. Like the Toyota Prius, this hybrid system uses its electric motor for extra boost, steady cruising, and creeping forward in heavy traffic. Audi estimates the A8 Hybrid would get 38 mpg, about a 100 percent improvement over a V-8 A8, while still making it to 60 mph in about 7.5 seconds.