Porsche 918 RS
While this car shares the name of the Porsche 918 hybrid supercar and, yes, this is a hybrid race car, the two vehicles have completely different hybrid systems.
This car, which is intended for track use only, has the same flywheel based hybrid system as Porsche's other hybrid racecar, the 911 GT3 R. It has only one seat, the space next to the driver being taken up by the flywheel.
The car's brakes generate electricity that spins the flywheel. Power from the spinning flywheel can then be turned back into electricity if the driver presses a button within eight seconds of braking. All told, the car can generate up to 767 horsepower.
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Last updated January 11 2011: 1:21 PM ET
