GM denies having 'lied' on Chevrolet Volt electric claims

General Motors has shifted into damage-control mode -- just like its bad ol' days -- as it fights media blasts about the new Chevrolet Volt "extended-range electric." Several news outlets charge that they were misled about Volt's powertrain and that it isn't as unconventional or gas-mileage thrifty as billed.

For the past couple of years, GM has insisted that the powertrain of its breakthrough car wasn't like a plug-in hybrid. The auxiliary gas engine in the car never directly drove the wheels, but only ran as needed to recharge the car's battery, which drives the wheels. That's why all, including Drive On, have called it an extended-range electric instead of a plug-in.

ALSO ON DRIVE ON: Test Drive's James R. Healey blows off the Volt tiff, but says the car is too pricey.

But with an embargo on driving impressions on the Volt having lifted, several say that the car's wheels are in effect -- if not directly-- driven by the engine when speeds exceed 70 miles per hour and the battery is depleted. Edmunds.com's Inside Line wrote a piece headlined "GM lied: Chevy Volt not a true EV." Popular Mechanics and Motor Trend both question GM's 230 mile-a-gallon claim, saying they received real-world mileage from the 20s to the 40s. Writes Ray Wert, editor-in-chief of Jalopnik.com:

It's enough for us to wonder why GM pushed the 230-mpg number in the first place and why they didn't just come clean on the powertrain this summer when asked a straightforward question.

As a result, GM has posted a full-throated defense on its media website. It says:

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.