GM and the EPA are in negotiations to figure out what kind of rating the new Chevy Volt will be getting. And it's not a minor consideration for GM. If the EPA treats the Volt as an electric vehicle, it may get a mpg rating of 100+ mpg. If the EPA treats it as a gas vehicle, the rating may be in the 40+ mpg (around what the Prius gets).
GM will want the Volt to stand out, especially against hybrids like the Prius. When you're going to cost twice as much as the competition, you need to be different.
If the EPA treats the Volt like gas cars, it will force the gas engine to run until the battery pack is fully recharged. If they treat it like an electric vehicle, the gas engine may not turn on at all during the testing of the vehicle.
Personally, I wish they would come up with a different classification for the Volt altogether. I want to know what the mpg is going to be like after I get to the 40 mile limit on the all electric power. I also want to know what it's going to be like during the first 40 miles (will the gas engine turn on for any reason to do anything?)
GM spokesman Dee Allen said the rating is far from set, stressing that what has been agreed to on a preliminary basis is that the Volt would be classified as an extended-range electric vehicle for the purpose of fuel-economy ratings.