GM claims unprecedented mileage for Volt

General Motors Co expects its Volt electric car to earn a fuel-economy rating of at least 230 miles per gallon for city driving, more than four times that of Toyota Motor Corp’s Prius hybrid, people familiar with the plans said. 

Chief Executive Officer Fritz Henderson will announce the rating and combined city-highway mileage of more than 100 mpg today at a new-vehicle exhibition at GM’s technical center in Warren, Michigan, said one of the people, who asked not to be identified because the details aren’t public. 

The Volt will receive “a higher number than anyone would expect,” GM Vice Chairman Bob Lutz, 77, said by e-mail on Monday. He wouldn’t say what the mileage will be. 

GM said in September it reached an agreement with the US Environmental Protection Agency on a testing method that would yield a rating of at least 100 mpg for the Volt, which will be able to go 40 miles (64 kilometers) on battery power before tapping an onboard gasoline engine for a recharge. 

The EPA hasn’t signed off on the 230 city mileage rating, one of the people said. 

Adora Andy, an agency spokeswoman, didn’t immediately return calls seeking comment after regular business hours. 

GM is counting on unproven technology to leapfrog the Prius, the world’s best-selling hybrid, which starts at $22,000. Lutz said in May that the Volt would probably cost about $40,000. 

The EPA rates the Prius as the most fuel-efficient car on US roads. The 2010 Prius is rated at 51 mpg in city driving and 48 mpg on the highway, according to the agency’s vehicle- efficiency website. 

Toyota sold 158,900 Priuses in the US last year, 12 per cent fewer than in 2007. 

The Volt may be produced in volumes of about 60,000 annually, once it goes on sale, GM has said. 

Real-world mileage varies depending on such things as driving style, weather and road conditions. 

Unlike conventional autos and hybrids such as the Prius, the 1.4-liter engine on the Volt won’t drive the wheels. Instead, it will only power the battery, which also can be recharged at a household outlet. The car is scheduled to go on sale late next year. 

The automaker, majority-owned by the US government since it emerged from bankruptcy on July 10, is speeding to remake itself. Henderson has said the Volt and the development of advanced batteries are priorities for the Detroit-based company. 

Toyota, based in Toyota City, Japan, fell 30 yen, or 0.7 per cent, to 4,120 yen at the 11 am trading break in Tokyo trading. The stock has gained 42 per cent this year.