MPGe (miles per gallon equivalent) is far from the best way to compare the efficiency of vehicles running on different energy sources, but as long as MPG is mandated by politicians in congress that disdain basic science, we'll have to live with it. That said, you might as well understand what it means before you go shopping for a new vehicle and it's actually not that complicated.
Reshared post from +Green Car Reports
Do you know what an MPGe is? Ford Motor Company breaks it down.
So What’s An ‘MPGe’ Anyway? Ford Explains It All For You
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 he…
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I prefer simply comparing cost per mile, or if you want something that doesn't fluctuate with prices, use Wh/mi (though Americans will probably prefer mi/kWh since they are used to bigger numbers being better).
MPGe is a bogus idea anyway — who cares how much energy is stored in a gallon of gasoline. You have all sorts of efficiency losses in the system (both for oil and electricity), so why do you choose these arbitrary places to measure? Why not consider the energy content in a barrel of crude oil? Or the energy used in refining or in electric transmission losses, etc?
The point is that these are very different ways of moving a car, and unless you go all the way back to the source of each (including mixing from multiple sources), then these points being measured are all arbitrary. What isn't arbitrary is what it actually costs to drive and the emissions (which is complicated in either case by mixed supplies).
I prefer simply comparing cost per mile, or if you want something that doesn't fluctuate with prices, use Wh/mi (though Americans will probably prefer mi/kWh since they are used to bigger numbers being better).
MPGe is a bogus idea anyway — who cares how much energy is stored in a gallon of gasoline. You have all sorts of efficiency losses in the system (both for oil and electricity), so why do you choose these arbitrary places to measure? Why not consider the energy content in a barrel of crude oil? Or the energy used in refining or in electric transmission losses, etc?
The point is that these are very different ways of moving a car, and unless you go all the way back to the source of each (including mixing from multiple sources), then these points being measured are all arbitrary. What isn't arbitrary is what it actually costs to drive and the emissions (which is complicated in either case by mixed supplies).
Like I said +John A. Tamplin, MPGe is a goofy way to do it. However, the 2007 energy bill that raised CAFE standards also mandated that ALL new vehicles must carry a window label with an MPG rating. Thus EPA and DOE had to come up with a way to show MPG for vehicles with plugs, CNG tanks, hydrogen tanks, etc. Thus MPGe was born.
Like I said +John A. Tamplin, MPGe is a goofy way to do it. However, the 2007 energy bill that raised CAFE standards also mandated that ALL new vehicles must carry a window label with an MPG rating. Thus EPA and DOE had to come up with a way to show MPG for vehicles with plugs, CNG tanks, hydrogen tanks, etc. Thus MPGe was born.
Yeah, and I suggest the lawmakers writing such bills are idiots, but I don't think I am giving you any new information :).
Yeah, and I suggest the lawmakers writing such bills are idiots, but I don't think I am giving you any new information :).