Electric cars are coming. The first mass produced electric car, the Chevy Volt, is due out later this month, with handful of other electric vehicles expected to be released next year. One issue concerning electric cars that has been hotly debated recently is what should electric cars list as their miles per gallon (MPG)? Here at BeFrugal.com, we think there is a better way for drivers to compare the MPG of these cars - by cost. Since traditional MPG doesn't fit with electric vehicles, we have come up with a new metric, cost equivalent MPG.