What is MPGe?

This month Ford proudly revealed that the new 2012 Ford Focus Electric will be the first all-electric five-seat vehicle to achieve a fuel efficiency rating of 100 MPGe. This sneaks it just ahead of Nissan LEAF, with a 99 MPGe rating, but a fair shot below the four-seat Mitsubishi i-MiEV, with its 112 MPGe rating.