General Motors Co. is disputing accusations that its low-emission Chevrolet Volt is a hybrid and not a true electric vehicle a month before the car goes on sale.
Auto critics Edmunds.com, Motor Trend and Popular Mechanics have said that during heavy acceleration the Volt uses its gasoline engine to power an electric generator which helps turn the wheels, similar to how hybrids run.
GM said on its website that the car is an extended-range electric vehicle, not a hybrid like Toyota Motor Corp.'s Prius.
The Volt debate illustrates the marketing challenge for automakers selling new technology in cars that don't fit standard classifications and whose performance is difficult to measure.
GM and Nissan Motor Co. have both made claims about their new models' fuel economy and driving range that not all consumers may attain because electric performance varies greatly by driving habits.
"You have a PR problem with any one of these vehicles," said Jim Hall, principal of 2953 Analytics Inc., an auto consulting firm in Birmingham, Michigan. "GM had this sort of schizophrenic thing about doing its best to manage perception and at the same time going off into traditional old-style GM hype."
GM has promoted the $41,000 Volt as an electric vehicle to give it an image boost over hybrid-electric cars such as the Prius.
The Detroit automaker has said for three years that the Volt would always run on electric power and more recently said it would average 230 miles per gallon. The U.S. Environmental Protection Agency hasn't rated that number, and GM said many consumers may get lower fuel economy.
GM said today that the engine does assist in driving the car through an electric generator.
Critics at Popular Mechanics and Edmunds both wrote they consider the Volt a plug-in hybrid and not the electric vehicle that GM has touted for years. The Edmunds review of the car had the headline: “GM Lied: Chevy Volt is not a true EV.”
Nick Richards, a GM spokesman, said the Volt always runs on electricity and has no mechanical link from the gasoline engine to the wheels.
The car's four-cylinder gasoline engine powers a secondary electric motor, which turns the wheels, Tony Posawatz, the Volt's vehicle line director, said in an interview. The car's gas engine doesn't directly power the wheels, he said. GM never disclosed that fact because the engineers saw it as a benefit that boosted the car's fuel economy, he said.
“I keep telling people that this is a smart solution,” Posawatz said. “It drives very different from a hybrid.”
Hall, of 2953 Analytics, said there are some similarities between the Volt and the Prius.
“In a Prius, there is no mechanical linkage between the engine and the wheels -- it goes through a motor,” he said. “They use the engine to drive a direct-drive generator to drive the motor. The Volt does the same thing, it's just that the Volt can run with electric power without an engine longer than pretty much any hybrid right now can.”
GM said previously that the Volt would go 40 miles on a fully charged battery before the gasoline engine starts to recharge the battery, giving the vehicle a total range of 340 miles.
The company said today it will go 25 to 50 miles in electric drive and 310 miles on one charge and a tank of fuel.
Nissan and GM both will have marketing challenges when consumers get lower range or fuel economy, Hall said. With hybrids and electric cars, they can drive farther in stop-and-go city driving than on the highway because braking recharges the battery.
That means many Volt owners won't get 230 miles per gallon in the Volt and Leaf drivers won't get the 100 miles on a single charge that the companies have claimed, Hall said.
Consumers probably won't care whether the Volt is a hybrid or electric car, said Eric Noble, president of The CarLab, an auto consulting firm in Orange, Calif. Potential buyers will be more concerned with the car's price, the fuel savings and how far they can drive before needing to plug in or refuel.
“Consumers don't care what we call it,” Noble said. “In our research, most of the questions from consumers are about battery life and recharging.”
The Volt's emissions are more important than what people call it, said Dan Becker, director of the Safe Climate Campaign, an environmental lobbying group in Washington.
“I don't think purity is the issue,” Becker said. “What comes out of the tailpipe is the issue. If it's a little, it's green. If it's a lot, it's not.”