Like it or not, MPGe is a plug-in electric car metric we'll have to live with, at least for now.

In this MPGe primer video, CNET's "Brian Cooley drills down on the new metric for rating MPG in cars like the BMW i8, Nissan Leaf and Chevy Volt."

It's actually rather easy to understand MPGe, but is this a useful metric for plug-in electric car buyers?  Considering that the EPA won't clutter its window sticker with tons of rating, should MPGe be replaced with something more useful?