The U.S. EPA has approved its fuel-economy label for the 100% electric Nissan Leaf, rating the vehicle as the “best” in the midsize vehicle class for fuel efficiency and “best” for the environment. The window sticker shows an equivalent 99 mpg for combined city and highway driving, allowing for comparisons with traditional gasoline-fueled vehicles. The 2011 Leaf, which uses no gasoline, was also rated best-in-class for the environment based on emitting zero greenhouse gases or other traditional tailpipe emissions. EPA-specific ratings are mpg equivalents of 106 city, 92 highway, for a combined 99 mpg. This calculation is based on the EPA’s formula of 33.7 kW·h being equivalent to the energy in 1 gal of gasoline. In addition, the label displays a charging time of 7 h on a 240-V charge and a driving range of 73 mi (117 km) on a full charge, though this will vary with real-world driving conditions. Sales of the Leaf begin in December in California, Oregon, Washington, Arizona, and Tennessee. In January 2011, sales begin in Texas and Hawaii, with additional market roll-out continuing later in 2011.