If you've been looking at buying a new electric car, you'll have noticed a slightly different measurement of economy on the official labels: MPGe.
But what does MPGe actually mean? Luckily, Ford is here to help you, so check out the video above to learn more.
Effectively, MPGe is a measure that lets consumers compare the familiar measure of fuel economy in gasoline and diesel cars--miles per gallon--with the very different energy use of electric cars.
Normally measured in kilowatt-hours (kWh), it isn't always easy to see how much of a benefit you might be getting by running an electric car.
Luckily, the U.S. Department of Energy's Argonne National Laboratory has measured the energy in gasoline, and deduced that one gallon of gasoline contains the equivalent of 33.7 kWh of electricity.
Once you can compare the two, it's a simple matter of converting the energy use of a given electric car into a figure in miles per gallon--even though no fossil fuel is being burned in the car.
That's how the 2012 Nissan Leaf's 34 kWh/100 miles is converted to 99 MPGe, and Ford's Focus Electric gets 105 MPGe combined from its 32 kWh/100 miles efficiency.
Some vehicles, like plug-in hybrids, get both MPGe and regular MPG measurements, to describe their efficiency both in electric vehicle mode, and in traditional hybrid mode.
For more, check out Ford's video--and leave any thoughts in the comment section below.