Volt gets 60 MPG EPA rating
With its ability to operate completely gasoline- and emissions-free for 25 to 50 miles and then continue indefinitely with its range- extending engine, the Volt’s energy efficiency depends on how you use it.
Because the Volt works like no other car before it, General Motors and the U.S. Environmental Protection Agency collaborated to design a new label to help consumers understand what to expect when they drive the Volt. Before plug-in cars like the Volt, calculating fuel economy was simply a matter of filling the tank with fuel, driving the vehicle and dividing the distance by the amount of fuel consumed.
Even though they have no tailpipe emissions, electric cars still use energy so the MPG equivalent (MPGe) is determined by measuring electricity use and converting it based on the energy content in a gallon of gasoline. This MPGe rating allows consumers to compare the Volt’s efficiency to other cars in its segment.
The Volt uses two energy sources, electricity from the grid, and gasoline from the pump, with the mix depending on how far you drive and how often you charge the battery. The Volt is a complex vehicle that is incredibly easy to use. And while the new fuel economy label also looks complex, it has more information than any EPA label before it.
The complex label, which the Environmental Protection Agency worked with G.M. to create, will rate the fuel economy of the Volt plug-in hybrid as 60 miles a gallon. The number was determined through E.P.A. tests that simulate various driving conditions and includes a combination of the gas engine and the battery.
Driven on battery power alone, the Volt has a fuel economy equivalent to 93 m.p.g., the E.P.A. determined, using a formula that converts kilowatt-hours of electricity to gallons of gas. The Volt’s gas engine was rated at 37 m.p.g.
The 93 and 37 m.p.g. figures appear most prominently on the window label, while the 60 m.p.g. figure is in much smaller type toward the bottom. The Nissan Leaf, a pure electric car, was rated this week as getting the equivalence of 99 m.p.g.
The label also shows that the cost to drive the Volt, which goes on sale in December in some parts of the United States, can vary from 4 cents a mile if the gasoline engine is never used to 9 cents a mile if the battery is never charged. The label shows the battery-only range for the Volt as 35 miles, a little less than the 40 miles that G.M. had estimated as the car was developed.
“We have said as often as we could that this will vary significantly with conditions and how you drive," Doug Parks, G.M.’s vehicle line executive for the Volt, said on a conference call with reporters. “If you try to boil this down to a single number it becomes quite difficult."
All of the numbers, of course, are well below the 230 m.p.g. rating that G.M.’s former chief executive, Fritz Henderson, said the Volt would receive in 2009. G.M. said that number was calculated based on a draft proposal for rating electric cars that the E.P.A. later rejected. (Nissan had said the Leaf, using the same proposed formula, would be rated at 367 m.p.g.)
The Volt’s label said driving the car 15,000 miles a year only on battery power would cost $601. That compares to an estimated annual cost of $561 for the Leaf.
The label shows a total range for the Volt, on a full charge and gas tank of 379 miles, including 344 on gas alone. G.M. says the Volt allows drivers to go much further than electric-only cars like the Leaf, eliminating a phenomenon it calls “range anxiety." That added convenience is a primary reason the Volt is priced $8,220 more than the Leaf, though both vehicles will be available to lease for about $350 a month.
The Volt is scheduled to go on sale first in California; Michigan; metropolitan New York; Austin, Tex.; and Washington, D.C. before becoming available in the rest of the country by 2012.
G.M. has said it plans to build about 10,000 Volts by the end of 2011 and 45,000 in 2012