Ask Americans about fuel-efficient cars, and many will name the iconic Toyota Prius hybrid, with gas mileage rated by the EPA at a combined 50 miles per gallon.

So you'd expect the EPA to rank the Prius as the best midsize car on its list of Most and Least Fuel Efficient Cars, right?

It's not there.

Instead, it's been displaced by the battery-electric 2011 Nissan Leaf, which doesn't use fuel at all. The EPA rates the Leaf electric car at a combined 99 MPGe, or equivalent miles per gallon.

A footnote on the EPA site explains, "MPGe is miles per gallon of gasoline-equivalent and represents the miles per amount of energy of a non-gasoline fuel that is equivalent to the amount of energy in a gallon of gasoline. For an EV or PHEV, 33.7 kilowatt-hours of electricity represents the same amount of energy as one gallon of gasoline."

2011 Nissan Leaf, Nashville, October 2010

2011 Nissan Leaf, Nashville, October 2010

But does this make sense? The majority of U.S. car buyers today likely aren't quite ready to buy a plug-in car, if indeed they could get one (orders for both the Leaf and the 2011 Chevy Volt are backlogged due to limited production).

But based on the EPA's best and worst list--which shows an automatic and a manual winner for each size category--potential buyers might completely ignore the Prius, unless they go into the larger list and sort by gas mileage.

Our reader (and Prius owner) John C. Briggs wrote to the EPA questioning the omission of the Prius from the list. On Monday, an unnamed EPA employee responded to Briggs, signing the note as "".

Here's what s/he wrote:

Our Best-Worst list shows the best automatic transmission vehicle and best manual transmission vehicle in each category. Because the Toyota Prius is classified as a midsize car and only comes with an automatic transmission, it is competing against the Nissan Leaf which has a rating of 106 city/92 Hwy (MPGe). The Hyundai Elantra is the most efficient manual transmission vehicle in that size class.

When you exclude EVs (there is a link at the top of the table that allows you to exclude EVs), the Prius replaces the Nissan Leaf as the most efficient Midsize car with an automatic transmission.

2011 Chevrolet Volt drive test, March 2011

2011 Chevrolet Volt drive test, March 2011

This is admittedly confusing, and we will soon be launching a redesigned version of this list. It is my understanding that we will be dropping the transmission distinction by next year and we will be simply listing the best in each category regardless of the transmission type.

When we initially came up with this list, it was typical for the vehicle with the top fuel economy to have a manual transmission.  It was pointed out that most people don't want a manual transmission and that it should show the top automatic as well. Since then automatic transmissions have improved and evolved with continuously variable transmissions,  automated dry double clutch transmissions, optional manual shift paddles on automatic transmissions, etc.

Now our current method for ranking vehicles is increasingly out of phase with the market. Hopefully we will be able to improve on this list soon.

Briggs comments, "Personally I think this shows the folly of MPGe as a metric and don't think the Nissan Leaf should be placed in the same category, but it is debatable."

Since we do a bit of software development here at High Gear Media, we have one very quick and simple suggestion for the EPA: Switch the list's default view to the one that excludes electric cars.

But then, make the link to include electric cars a whole lot more visible.

There! We've done our bit to improve government for the day. If only Congress and the President could manage to do the same thing....


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