According to GM's materials on the Volt

According to GM's materials on the Volt In an article being echoed around the Web, Motor Trend reporter Frank Markus lays out in detail how the Chevy Volt transmits power to its wheels. And unlike GM's press releases claim for the car, the power does not solely come from the electric motors.

According to GM's materials on the Volt, "When the battery energy is depleted, the Volt seamlessly transitions to extended-range mode. Power is inverted from a technically advanced, 1.4L 63-kW (84-hp) gasoline-powered onboard engine to the electric drive unit to provide up to 310 additional miles of range."

But GM left some information out. Markus writes that both the electric motors and gas engine connect to a planetary gearset, which in turn drives the wheels. Most of the time, the electric motors turn the gearset.