GM Volt posts 1.2L/100km

The ‘range-extender’ plug-in electric vehicle, which goes into production later this year and is due in Australia with a Holden badge during 2012, uses a low-emission flex-fuel engine to charge on-board batteries.

GM's early testing suggests the Volt's city-cycle fuel economy could be at least 230 miles per gallon - or 1.2 litres per 100km, based on draft EPA federal fuel economy methodology for plug-in electric vehicles.

GM says the Volt has the potential to travel up to 64km on electric-only propulsion from a single battery charge, with a 480km-plus range with its flex fuel-powered engine-generator.

GM CEO Fritz Henderson said the early figures from the Volt would mean the new car is a ‘game-changer’ for the brand. "From the data we've seen, many Chevy Volt drivers may be able to be in pure electric mode on a daily basis without having to use any gas," he said.

"EPA labels are a yardstick for customers to compare the fuel efficiency of vehicles. So, a vehicle like the Volt that achieves a composite triple-digit fuel economy is a game-changer."

According to US Department of Transportation data, nearly 80 per cent of Americans commute less than 64km a day. Mr Henderson said the Volt's high-mileage performance would require plugging the car into the electric grid at least once each day and would also depend on cargo, passengers and air conditioner use.

During GM's testing of pre-production prototypes the Volt has achieved 64km of electric-only, petroleum-free driving in both EPA city and highway test cycles. GM expects the Volt to consume as little as 25 kilowatt hours per 161km in city driving, which would cost around 3 US cents per 1.61km, based on the average cost of US electricity. GM says using the US average cost of electricity (approximately 11 U.S. cents per kWh), a typical Volt driver would pay about US$2.75 for electricity to travel 161km.

The Volt is powered primarily by electrical energy stored in its 16 kWh lithium-ion battery pack, but when the battery runs low, an engine-generator produces electricity to power the vehicle.