Report: Chevy Volt is More Straight Hybrid Than We Knew is claiming exclusive access to information that has, to this point, been left to the wild rumors of the internet: The Chevy Volt’s engine may actually directly power the car’s wheels during some kinds of driving.

If this is true, it would be big news for a car and a company that, up ’til now have gone to great lengths to brand and market the vehicle in a new category—the Extended Range Electric Vehicle (EREV)—while simultaneously distancing the Volt from the more widely used moniker, Plug-in Hybrid Electric Vehicle (PHEV)… all of which was done to avoid branding the Volt in the hybrid category and associate it with pure electric vehicles.

Electric drivetrains come in many shapes and sizes, so here’s a quick recap of the issue for those of you that may be confused (and I’m simplifying here, so those engineers among you please cut me some slack):

  • On one end of the spectrum you have your regular hybrid vehicles—like the Toyota Prius or the Ford Fusion Hybrid.
    • These vehicles are Frankenstein contraptions that have both a full electric drivetrain and combustion engine drivetrain crammed into them.
    • Depending on the driving conditions, either one or both drivetrains are engaged to reach the maximum fuel efficiency.
    • Notably, of course, you can’t plug regular hybrids in.
  • On the other end of the spectrum you have pure battery electric drivetrains—like the Nissan LEAF.
    • These vehicles only have a big battery and when the battery is drained, the car stops.
    • They have no combustion engine whatsoever
  • In between you have PHEVs and EREVs.
    • The differences between the two are largely semantic and a matter of debate for those of us that geek out on these things, but for the vast majority of folks the differences mean very little… but for clarity’s sake:
      • PHEVs are cars like the Toyota Prius Plug-in, which is basically a Prius with a bigger battery that can use its electric drivetrain alone for about 12 miles after charging, at which point the car turns back into a regular Prius hybrid.
      • EREVs are a category that GM essentially coined specifically for the Volt, that, as we’ve known to this point, don’t have a direct mechanical linkage between the on-board engine and the wheels. Instead, when the battery runs out of juice after charging, the smallish engine turns on and runs a generator which charges the batteries for additional range.

So as you can see from the above spectrum, it would be entirely surprising—nay, shocking—to hear that GM has kept the fact that the Volt actually has a direct mechanical linkage between the engine and the wheels secret to within 4 months of the car’s launch. But, according to Rob Peterson, General Motors spokesperson, as quoted over at, the Volt WILL use some sort of traditional hybrid efficiency strategies. While not being more forthcoming than that—GM plans to detail these strategies at a conference in January 2011—he did make it clear that some of these technologies and strategies are borrowed from GM’s work with regular hybrids.

In addition, GM has now apparently started the damage control aspect of this revelation by downplaying the significance of the EREV moniker they developed specifically for the Volt with Peterson saying he’s “all right” with people calling it a plug-in hybrid.

What do you guys think? A non-issue, or another reason to distrust GM’s second coming of the plug-in car?

Nick Chambers

Not your traditional car guy.