Driving this weekend? Look for GPMs, not MPGs

Daniel L. Squadron

June 06, 2011

NY Daily News



Saturday, May 28, 2011

As summer unofficially begins this Memorial Day weekend, millions of Americans will take to the road, spending billions of dollars on fuel. As the costs add up, we'll be reminded yet again that buying a car is not just a one-time expense.

The Department of Transportation and Environmental Protection Agency just mandated new fuel economy window stickers. These go a long way toward cutting costs and limiting the effect of fuel usage on our environment.

There's a lot of new and complicated information on these labels - dollar savings, greenhouse gas and smog ratings, estimated costs and, of course, the standard miles per gallon calculation. However, what might be the key piece of information for comparative shoppers is the smallest number on the whole sticker: gallons per 100 miles.

Right now, consumers use the standard miles per gallon (mpg) calculation to compare fuel efficiency. And it seems pretty straightforward: It's obvious that a Hummer (16 mpg) will burn a lot more gas over time than a Prius (46 mpg).

But when consumers try to compare relative efficiency, as they usually do, the miles per gallon measurement falls short. For example, take this pop quiz: Two families want to save money on gas. Family A upgrades from a 10 mpg to a 15 mpg light truck. Family B upgrades from a 25 mpg to a 45 mpg sedan. Over the next 1,000 miles, who has saved more gas?

If you chose Family B, you'd be like most people - and you'd be wrong. Over 1,000 miles, switching from 10 to 15 mpg will save you 33 gallons. Switching from 25 to 45 MPG will only save you 18 gallons.

Don't worry, studies show that most consumers get miles per gallon comparisons wrong, as I did when I first took the quiz. But at the dealership, getting this question wrong is bad - for your wallet and the environment.

Ultimately, the most important question for consumers is basic: Given the numbers of miles I drive (the daily commute, trips to soccer practice, the annual pilgrimage to Florida) and the type of car I need (most people are not choosing between a Hummer and a Prius), how many gallons of gas will I actually need to buy?

To answer this question correctly consumers need to know their GPM - their gallons per mile.

GPM measures how much fuel must be burned in order to go a set distance. Multiply the sticker's listed "gallons per 100 miles" by the price of gas in your neighborhood and you know exactly how much it will cost you to drive 100 miles - and therefore compare how much gas you would have to buy for each car on the lot.

In 2009, I introduced a bill that would require auto dealers to affix GPM "fuel impact statements" on all new vehicles sold in New York State, to help consumers choose the most affordable and efficient vehicles. Now, with the new federal labels, I'm pleased that my bill is no longer necessary.

For one family, better information about their cost of gas can save hundreds of dollars in a year. When you multiply that by the millions of cars sold in the United States each year, the fuel savings is in the billions - and that's a big step in the fight against climate change.

But consumers need to know to look for GPM on the new window labels. It's the little number just below the MPG. Knowing how much fuel your new car will actually use: not a bad achievement for a little sticker in a car lot.

Squadron is a state senator representing parts of Brooklyn and Manhattan.

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