From the Leaf features:
"The Nissan LEAF® gets you the equivalent of 106 miles per gallon without using a single drop of gas. [*] There are zero emissions, so it doesn't even need a tailpipe. The advanced 80kW AC synchronous electric motor provides the quietest, smoothest ride you've ever experienced. Say goodbye to the vibration and engine noise of every other car you've ever driven. And the battery, which is half the weight and twice the power of the nickel-metal hydride batteries used in hybrids, gives you an ultra-efficient ride."
Nissan explains the conversion between a regular gasoline engine mileage and an electric motor mileage as:
"2012 EPA Fuel Economy Estimates. Based on EPA formula of 33.7 kW/hour equal to one gallon of gasoline energy, EPA rated the LEAF equivalent to 106 MPG measured as gasoline fuel efficiency in city driving. Actual mileage may vary with driving conditions - use for comparison only."
The range of the Leaf will vary based on driving conditions. On the Leaf Range feature of their website, they list the distance the Leaf can go in some of the following conditions:
IDEAL DRIVING CONDITIONS
Distance: 138 miles
Speed: Constant 38 mph
Temperature: 68 degrees
Climate control: Off
Suburban driving on a nice day
Distance: 105 miles
Speed: Average 24 mph
Temperature: 72 degrees
Climate control: Off
Cross-town commute on a hot day
Distance: 68 miles
Speed: Average 49 mph
Temperature: 110 degrees
Climate control: On
Winter, urban stop-and-go, traffic jam
Distance: 62 miles
Speed: Average 15 mph
Temperature: 14 degrees
Climate control: On
There are two versions of the Leaf: The SV and SL. The biggest difference between the two is the addition of a quick charge port on the SL version. The quick charge port comes in handy if you have electric car level 3 charging, or higher voltage charging for faster recharge times (using 480 V).
Car and Driver has a nice comparison between the Nissan Leaf and its closest competitor, the Ford Focus Electric:
"According to EPA tests, the Ford EV has a range of 76 miles on a single charge; on the same test, the Leaf scores 73. The Focus is slightly more efficient than the Leaf and returns a combined mileage number of 105 MPGe (miles per gallon equivalent) compared with the Leaf’s 99. That means the electric Focus can travel 100 miles for about 25 cents less than the Leaf. We saw 94 MPGe in our short test, and managed an 83-mile range on a trip that was roughly half city and half highway driving.
Another advantage for the Ford is that recharging the Focus’s 23-kWh lithium-ion battery from empty takes three to four hours on 240-volt power, or nearly half the time required for the Leaf (although we hear that Nissan will be upgrading the car's onboard charger for quicker refills soon). On 120 volts, a full charge of the Ford takes about 20 hours. Ford credits the battery’s highly effective cooling system for this. Unlike what Nissan offers for the Leaf, Ford isn’t making available a quick-charge 440-volt plug on the Focus, but there is less need for one."
You can see the Mapawatt product page for the Ford Focus EV here.
Interior Size:
"The Nissan LEAF® is all about efficiency, but that doesn't mean we've skimped on either interior finish or size. It's a 5-door, 5-passenger hatchback featuring heated front and rear seats, a heated steering wheel, and a 60/40-split fold-down rear seat that, when down, provides a spacious 24 cubic feet of cargo volume. The stylish, modern, and comfortable light grey seats are partially made from recycled bottles."