General Motors today unfurled mileage figures for the upcoming Chevy Volt and, as expected, it's a complicated affair.

The Volt largely drives on electricity, but it also sports a gas generator that helps power the car over long distances. On batteries alone, it gets the equivalent of 93 miles per gallon, close to the 99 MPG rating for the Nissan Leaf and way higher than anything else in its class. On gas alone, the car gets 37 miles per gallon. The Volt, however, rarely drives on gas alone.

In the end, the EPA gave it a blended rating of 60 MPG.

But, as the video below shows, the results vary from driver to driver and street to street. I'm the one driving the car, and I'm driving the Volt in my hilly neighborhood in San Francisco. Listen for the rumbling sound in the background. That is the gas generator continually flipping into action. The generator kept coming alive because I kept flooring the car (bad habits and terrain). Additionally, the Volt was in performance, not economy, mode. In more ideal circumstances, the generator comes much less and the battery does more work. (Editor's note: originally I thought we were still in full EV mode, but we were in extended range mode where the generator kicks on to charge the batteries. The Volt kicks into extended range mode when the battery goes to around 20 percent of state of charge.)

"You have requested torque and so we have to provide electricity to meet that demand," he told me.

In the end, the test drive resulted in one of the worst mileage rating the GM representative had ever seen. In fact, the car's economy rating metrics gave me a rating of zero. Again, It wasn't the fault of the car. The Volt is fun to drive, it didn't sag on the hills and held four people comfortably. ("This is way better than my dad's PT Cruiser," said one of the ten-year-old passengers.) It was pure operator error.

Still, it demonstrates how ranking all-electrics and plug-in hybrids will be challenging.


And here's a view of the interior console.