Illusion of Miles Per Gallon

(This information was recommended by T. Patrick Burke)

Richard Larrick and Jack Soll of Duke University ran a series of experiments to show that the current standard of miles per gallon leads consumers to believe that fuel consumption is reduced at an even rate as efficiency improves. But that’s not the case.

Soll and Larrick offered an alternative metric: gallons per mile. Expressed in gallons used per 100 miles, 18 m.p.g. becomes 5.5 gallons per 100 miles, and 28 m.p.g. becomes 3.6 gallons per 100 miles. And the difference is suddenly obvious: nearly two gallons every 100 miles, or a difference of more than $8.
Many European countries already list efficiency in terms of volume per distance traveled (liters per 100 kilometers or L/100km).

“Miles per gallon is misleading and can play tricks on our intuitions,” Prof. Soll said in a press release, which also links to an interactive quiz.

Source: New York Times Blog by Richard Chang June 20 2008