The car of the future will be powered by hydrogen. No, wait, ethanol. No, electric batteries. Though the automobile is clearly at a crossroads, no one knows exactly which clean technology will succeed the gasoline-powered engine. That's why General Motors' E-Flex system is smart. Introduced early this year on its concept electric car, the Chevrolet Volt, the E-Flex platform can be adapted to run on an electric battery, a hydrogen fuel cell, ethanol or standard gasoline. That gives GM the flexibility to adapt to what lies ahead.
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