Study from MIT finds fuel efficiency has not improved much

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Honda Accord

Modern cars would get better gas mileage if they weren't so heavy. Image from Wikimedia Commons.

Most car companies use fuel efficiency as part of their overall marketing schemes. However, a recently released study by an MIT economist found that cars haven’t been gaining as much fuel economy as commercials would have us believe.

TV is lying to us again

Just about every car maker emphasizes the fuel efficiency for some, if not all, of the cars produced by that manufacturer. Obviously, there are exceptions; Bugatti isn’t going to be caught lauding the economy inherent to the 16-cylinder, quad-turbocharged Veyron.

There is also a belief that in the past decade or two, great gains have been made in the realm of fuel economy. Car makers are thought to be making cars that are more fuel efficient than the autos of yesteryear and, to an extent, it is true. However, an economist from the Massachusetts Institute of Technology recently published a study asserting that fuel economy gains have been fairly modest.

Numbers don’t lie

Christopher Knittel, according to USA Today, recently published a paper entitled “Automobiles on Steroids” in the American Economic Review, an academic journal, concerning certain characteristics of cars made between 1980 and 2006. Among other findings, he discovered the average gas mileage across a large number of models has increased by only 15 percent over that period, though the average engine gained 60 percent fuel economy in that period.

The average fuel economy in 1980 was 23 miles per gallon, which had improved to only 27 miles per gallon by 2006.

The heavy truth

The reason for the modest gain in gas mileage is that cars have become heavier and have gained more horsepower. According to the New York Times, the average car, excluding body styles such as vans, trucks or SUVs, weighed in at 3,041 pounds in 1980. By 2006, the average car had ballooned to 3,455 pounds. The average curb weight across all vehicles, including trucks, etc., in the study in 2006, was 26 percent heavier and 107 percent more powerful than the average vehicle in 1980, according to the Washington Post.

For instance, the Honda Accord was achieving gas mileage of more than 34 miles per gallon by 1983, declined to less than 29 mpg after 1990 and creeped back up to slightly more than 30 mpg by 2005. The Accord also gained almost 1,000 pounds in weight and more than 100 horsepower in that time.

Weight and power cancels efficiency

All that engine technology, according to Knittel, has gone into compensating for the excess horsepower and weight. If cars were the same average weight and power of cars in 1980, the average mileage would be 37 miles per gallon.

Knittel also argues that instead of increasing CAFE standards, which is politically expedient, the government should raise gas taxes instead. That way, according to the New York Times, car makers would have an incentive to boost gas mileage even further, and it would get people to drive less.


USA Today

Washington Post

New York Times

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