Recognizing that all-electric vehicles have a serious drawback when it comes to range, General Motors created the Voltec (or E-Flex) system. It consists of an electric motor, a battery for storing energy and a gas engine that serves as a generator. And this is exactly what you find in the Chevrolet Volt. Its electric motor produces the equivalent of 149 hp and its batteries are of the lithium-ion variety. Drivers who keep their distances under 65 km per day will never use the gas engine!