230 MPG For Chevy Volt? Not Likely
by Reilly Brennan (AOL Autos) EPA Mulls New Fuel Economy Guidelines
The U.S. Environmental Protection Agency will soon draft a new regulation for the way it calculates fuel efficiency for electric cars, potentially deflating the stratospheric fuel economy numbers trumpeted by automakers in recent months.
In August 2009, GM announced that its new 2011 Chevy Volt hybrid would achieve a stratospheric 230 “miles per gallon,” using a calculation that took into account how the vehicle would fare given its sometimes-battery, sometimes-gasoline engine power source. Nissan responded with its own number for its new Leaf electric car, 367 MPG, setting off something of an arms race for efficiency. Without actual guidelines from the EPA, however, the public will be left wondering where these numbers come from — and whether they’re believable.
…GM’s calculation takes into account only the gasoline used, while Nissan’s number was merely an equivalent since its Leaf only runs on electricity. …GM came up with the Volt’s number using a guideline from the Society of Automotive Engineers, one that ran the car through a city driving simulation. …dividing the total distance travelled by the amount of gasoline burned. But for a good portion of the test, the Volt was operating on battery power alone, having started the test with a full battery. This effectively adds the 40 miles of battery range to the distance travelled, hence the big mileage number. …
Nissan is pulling for a new standard that looks at electricity use not in terms of a miles-per-gallon equivalent (although the company admits it did do this with its 367 MPG claim), but something that takes into account grams of C02 or kilowatts. READ MORE