A really neat technology has been demonstrated in a creative way in the struggle to use gas more efficiently in cars. The Mazda RX-9 is the most futuristic car I’ve seen in awhile. Specialized, “slick skin,” plastic body panels get an electric charge as air rushes by it, which in turn provides power to the electric motor.
The same car with slick skin also has slick wheels. The tires” feature Electroactive Polymers (E.A.P.) that with varying levels of voltage from the vehicle’s electrical system can actually change the shape and depth of their tread pattern. The rubber donuts can go from flat and smooth to knobby and grippy, or even ride high on their centers for ultra-low rolling resistance. “