So it's come down to this, has it? The U.S. car-buying public is apparently so stupid that the Environmental Protection Agency has to rate the efficiency of an all-electric car that burns no gasoline in ... miles per gallon.

[facepalm]

That's the only possible reaction to the news this afternoon that the EPA has approved a "fuel-economy" label for the 2011 Nissan Leaf electric car showing a rating of 99 "miles per gallon equivalent."

2011 Nissan Leaf window sticker showing 99-MPG

2011 Nissan Leaf window sticker showing 99-MPG

The ratings for the gasoline the Leaf doesn't burn in the city is 106 "MPGe" and the rating for the fuel it can't use in highway travel is 92 MPGe.

There is actually method to the EPA's madness. The energy content of 1 gallon of gasoline is 33.7 kilowatt-hours. The 2011 Nissan Leaf has a 24-kWh battery pack of which it uses approximately 80 percent.

And the EPA calculates a driving range of 73 miles in its combined cycles, "based on the five-cycle tests using varying driving conditions and climate control." Just as "your mileage may vary," electric-car range depends on a variety of factors, including speed, aggressiveness, outside temperature, and number of accessories used.

2011 Nissan Leaf, Nashville, October 2010

2011 Nissan Leaf, Nashville, October 2010

As well as the 99-MPGe rating, the Leaf's window sticker will also display a charging time of 7 hours using 240-Volt charging station.

The basic message, though, is that the 2011 Nissan Leaf is best for the environment and best in its midsize vehicle class for its gas mileage. Even if it doesn't actually use any. Which is, we suppose, definitely best.

Sheesh.

[For everything we've published on the Nissan Leaf, winner of GreenCarReports' 2011 Best Car To Buy Award, see our Ultimate Guide to the 2011 Nissan Leaf.]

So if we're so smart, what would we do? We think the American public is quite capable of dealing with energy measured in kilowatt-hours. We've been doing it with our electric bills for, oh, what, 50 years or so?

So why not a simple metric saying how many kilowatt-hours an electric car would use to go 100 miles? That way, you could do a quick calculation and say, for instance, that the 34.0 kWh it would take for the Leaf to go 100 miles would cost you $3.40 (if your electricity costs 10 cents/kWh).

Which pretty much anyone can at least sense is way lower than the $12 it would take a 25-mpg car to go that same 100 miles on $3/gallon gas.

It would also allow you to compare efficiencies among different electric vehicles. How would the 2011 Leaf compare to, say, next year's 2012 Mitsubishi "I" in efficiency of energy use? The lower the number of kWh used to travel 100 miles, the better the efficiency.

We're tempted to reprise our whole "MPG is stupid" topic, complete with confirmation from the National Research Council.

But, hey, look at all the good that did. Now we've got electric cars with "gas mileage."

It's enough to make us want an adult beverage. Or three.

[Nissan]