Nissan's Leaf, a battery car aimed at attracting environmentally conscious drivers, will use the equivalent of 2.4 litres/100km in a combined cycle, based on US government testing.
Nissan says the Environmental Protection Agency's fuel efficiency window sticker, which provides information about the car's energy use, would rate it at 2.2 litres/100km in city driving and 2.6 on the highway.
The EPA tests show the Leaf can travel 117km on a fully charged battery and will cost $561 (R3900) a year in electricity. Nissan has said the Leaf can travel 160 miles on a full charge, based on tests used by California regulators.
Both Nissan and GM wil release battery cars within weeks in the auto industry's most prominent attempt at mass-producing vehicles that shift away from conventional fuels.
The Leaf doesn't have a combustion engine and must be recharged once its battery is flat - but the tests show equivalent fuel efficiency of nearly twice the Toyota Prius, which uses 4.7 litres in combined driving.
GM's entry, the Chevrolet Volt, uses battery power for the first 40-80km a small petrol engine to create an additional charge for another 500km. GM has not yet revealed the fuel-consumption rating for the Volt.
Nissan North America director of product planning and strategy, Mark Perry, said the vehicle's range would vary based on driving conditions. Tests conducted by the Federal Trade Commission, which regulates advertising claims, had estimated a range of 150-170km per full charge and the company's internal tests had found a broader range of 100-220km, Perry said. The California Air Resources Board estimated a range of 160km.
Perry insisted: “As we've said all along, your range varies on driving conditions, temperature, terrain and we've talked very openly about this idea of a range of ranges. The Leaf's label will indicate the vehicle is the best in class in fuel efficiency and tailpipe emissions.”
Nissan will start selling the Leaf in California, Washington, Oregon, Arizona and Tennessee in December 2010 at $32 780 (R225 000). It'll be available throughout the US by the end of 2011 and worldwide - including South Africa - in 2012.
The Volt will sell for $41 000 (R280 000) and GM will sell it first in California, then nationwide in 12-18 months.
Each vehicle qualifies for a $7500 (R52 000) federal tax credit and some states and communities are offering additional tax breaks that will further lower the price.
GM spokesman Greg Martin said the automaker was working with the EPA and expected to announce details of the Volt's mileage estimates soon.
The Leaf's equivalent fuel consumption was based on a formula that says 8.9 kilowatts per hour holds the energy equivalent of litre of petrol. Charging time is estimated at seven hours on 220 volts and the cost estimate is based on 24 000km per year and 12 US cents (R0.85) per kilowatt-hour. - Sapa-AP