As GM has started the media launch program for the Chevrolet Volt, some confusion has emerged about details of the Volt’s drive technology.
The engineering of the Voltec electric drive unit is very sophisticated. As part of the media launch, we're diving deeper into how the system works than we have in the past. We did not share all the details until now because the information was competitive and we awaited patent approvals. Following a small number of inaccurate media reports, we want to clarify a few points.
The Volt has an innovative electric drive system that can deliver power in both pure electric and extended range driving. The Voltec electric drive cannot operate without power from the electric motors. If the traction motor is disabled, the range-extending internal combustion engine cannot drive the vehicle by itself.
There is no direct mechanical connection (fixed gear ratio) between the Volt’s extended-range 1.4L engine and the drive wheels. In extended-range driving, the engine generates power that is fed through the drive unit and is balanced by the generator and traction motor. The resulting power flow provides a 10 to 15 percent improvement in highway fuel economy.
Our overriding objective in developing the Voltec electric drive was to deliver the most efficient, yet fun-to-drive experience in both pure electric and extended-range driving. We think our unique technology lives up to its most important promise: delivering our customers with the only EV that can be their primary vehicle, with EV operation for normal daily driving, and extended range driving for weekends, holidays, and longer trips – all with no range anxiety.