The U.S. Environmental Protection Agency (EPA) has given the 2011 Nissan Leaf a mileage rating of 99 miles per gallon (mpg); besides dubbing the electric car to be the best for fuel efficiency and the environment.

The Environmental Protection Agency (EPA) has approved its fuel-economy label for the 100-percent electric Nissan LEAF, rating the vehicle to be 'best' in the midsize vehicle class for fuel efficiency and 'best' for the environment, EPA was quoted as saying in a statement.

The EPA estimated that the Leaf, in kilowatts per hour, would use the same as 106 miles per gallon of gasoline in city driving and 92 miles per gallon in highway driving, Nissan said in a statement.

This calculation is based on the EPA's formula of 33.7kW-hrs being equivalent to one gallon gasoline energy. In addition, the label displays a charging time of seven hours on a 240V charge and a driving range of 73 miles, based on the five-cycle tests using varying driving conditions and climate controls, the carmaker said.

We're pleased the label clearly demonstrates the Nissan LEAF to be a best-in-class option, reflecting that it's a pure electric vehicle, uses no gas, has no tailpipe and has zero emissions, said Scott Becker, senior vice president, Finance and Administration, Nissan Americas. The label provides consumers with a tool to compare alternative-fuel vehicles to those with a traditional internal combustion engine and allows them to make an informed purchase decision.

Nissan leaf will begin sales in December in California, Oregon, Washington, Arizona and Tennessee, the statement said. It will also extend sales in Texas and Hawaii by January 2011.

Nissan has priced Leaf at $32,780. When it goes on sale in the US, as an all-electric vehicle, the Leaf will qualify for a $7,500 federal tax credit, which brings down the price to $25,280.

According to a recent report from Bloomberg New Energy Finance, plug-in electric vehicles, including plug-in hybrids and battery electric vehicles, have the potential to make up 9% of auto sales in 2020 and 22% in 2030 (1.6 million and 4 million vehicle sales respectively).