The Wildfire Motors WF650-C, while not an electric automobile, does claim an impressive 60-70 miles per gallon. This is a 3 wheeled "motorcycle", and is registered as a motorcycle in the United States.
The Wildfire has a 26 horsepower engine with a top speed of 65 miles per hour. It also has a 4 speed manual transmission. The load capacity is 800 lbs. This looks like a good little car for driving around town, and running errands. Does not appear to have seat belts (since technically a motorcycle), so not recommended for kids to ride.