Crosscut

You don't need a hybrid to guzzle less

By Knute Berger

June 23, 2008

Driving an economy beater may help the planet in some small way, but most people are looking for a more fuel-efficient ride. Would you recognize one if the miles-per-gallon rating was staring you in the face? Probably not, according to two Duke University professors, Richard Larrick and Jack Soll, who published the results of a study in the latest Science.

Here's how The New York Times reported their findings:

Quiz time: Which of the following would save more fuel?

a) Replacing a compact car that gets 34 miles a gallon with a hybrid that gets 54 m.p.g.

b) Replacing from an S.U.V. that gets 18 m.p.g. with a sedan that gets 28 m.p.g.

c) Both changes save the same amount of fuel.

Most people pick a. But, that would be wrong:

The correct answer is b. In fact, going from 18 m.p.g. to 28 m.p.g. saves more than twice as much fuel as going from 34 m.p.g. to 54 m.p.g. (198 gallons vs. 94 gallons), according to two management professors from Duke University.

The Duke researchers say that people assume larger m.p.g. numbers automatically mean more savings. That's an illusion caused by the traditional miles-per-gallon calculation. They argue that fuel savings are better calculated by determining gallons-per-mile. According to the Times, "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. ..." Many European countries already use a similar calculation (liters-per-100-kilometers). That would provide a more accurate picture that emphasizes not how far you can go, but how much fuel you'll use to get there. That makes it easier be aware of cost and conservation.

While a new hybrid would still use less gas, smaller, incremental upgrades in fuel efficiency can result in significant savings too. According to Science Daily, "If you switched from a 12 m.p.g. S.U.V. to a 15 m.p.g. S.U.V., you would save approximately 167 gallons of fuel over 10,000 miles. At a cost of $4 a gallon, that's roughly $700."

So, you can have a big impact on your pocket book and the planet even if you make a modest upgrade. This would help address issues faced by people who can't easily downsize their vehicles, folks who need mini-vans for big families or pick-up trucks for work.

Knute Berger is Mossback, Crosscut's chief Northwest native. He also writes the monthly Gray Matters column for Seattle magazine and is a weekly Friday guest on Weekday on KUOW-FM (94.9). His new book, Pugetopolis: A Mossback Takes On Growth Addicts, Weather Wimps, and the Myth of Seattle Nice, has just been published by Sasquatch Books. You can e-mail him at mossback@crosscut.com.

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Printed on November 07, 2009