Fourth-greenest car: Nissan Leaf
Combined city/highway mileage: 99 mpge (2012 estimate)
Nissan just knocked $6,400 off of the Leaf's starting price, making for the U.S.' least-expensive mainstream electric car.
The Japanese automaker brought the Leaf to America in the 2011 model year, offering U.S. drivers the chance to get the equivalent of nearly 100 mpg fuel efficiency.Designed to look and feel like any other small four-door hatchback, the $28,800 Leaf relies on a 107-horsepower electric motor to get around. The 2012 Leaf only went about 73 miles between charges; Nissan says this year's version will have a longer range but hasn't yet released exact figures for range or mpge. And while charging up a Leaf takes around 21 hours using a standard 120-volt wall socket, you can cut that to around four hours with a 240-volt outlet and an optional 6.6-kilowatt onboard charger.