GM delivers a jolt with Volt

Says its hybrid car will get 230 mpg in city driving

August 12, 2009|By Martin Zimmerman, TRIBUNE NEWSPAPERS

General Motors Co. says its long-awaited Chevrolet Volt plug-in hybrid is expected to achieve fuel economy of 230 miles per gallon in city driving.

That would give the Volt, which is expected in showrooms late next year, the highest fuel efficiency rating of any car rated by the Environmental Protection Agency. The current EPA mileage leader is the Toyota Prius hybrid, which gets 50 mpg in combined city-highway driving. The Volt is designed to run on electric power only for about 40 miles, after which a small gasoline engine kicks in to recharge the battery, giving it a range of more than 300 miles. The battery can be recharged by plugging in to a home outlet.

GM's estimated mileage for the Volt is based on city driving, where it can take full advantage of its all-electric capability. Highway mileage would be lower because it would require more work from the gasoline engine.

Although GM has not released pricing information on the Volt, industry analysts estimate it will cost about $40,000. Analysts expect Volt owners would be eligible for the $7,500 federal tax credit provided on electric vehicles.

The automaker's fuel economy estimates still must be confirmed by the EPA, which is developing a new methodology for calculating fuel economy for cars that can travel significant distances powered only by electricity.

The mileage estimate doesn't include a measurement of the cost of the electricity needed to charge the Volt's nearly 400-pound lithium-ion battery, causing some analysts to question the usefulness of the number.

Electric-vehicle proponents, although encouraged by the Volt's preliminary numbers, cautioned GM not to overstate the car's capabilities. "It would be a real shame if such a promising technology got a bad rap because they raised expectations too high," said Jim Kliesch, a senior engineer with the Union of Concerned Scientists.

GM has staked much of its technological reputation on the Volt. Critics have derided the vehicle as an expensive piece of "vaporware" that would never achieve significant sales.

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How the Volt works

1. Lithium-ion battery: Provides power to the electric drive unit. It can run the car for 40 miles before running low on energy.

2. Electric drive: Runs the Volt, making it move.

3. Gas engine: Powers the electric drive unit when the battery runs low and can recharge the battery when the car is running.