MIT Researcher Explains Why Fuel Economy is Still Low Despite Advances in Fuel Efficiency

By Cody Burke on 5 January 2012
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If you’ve ever wondered why cars in far-off lands seem so much more fuel efficient than the vehicles available in the United States, you are not alone.  Christopher Knittel,  professor of energy economics at MIT, wondered about this as well.

Knittel has found that the reason that U.S. car fuel efficiency lags behind other countries is mainly due to a focus on maintaining large sized cars by improving efficiency per pound of weight, not overall efficiency.

Knittle’s study (based on data from the National Highway Traffic Safety Administration) found that, although technology advances have achieved increased theoretical fuel efficiency for U.S. vehicles of 60% between 1980 and 2006, cars also got 26% larger on average and increased horsepower by an average of 107 hp.  The increase in size and horsepower kept actual average fuel efficiency gains to only 15%.

Knittle notes that automakers are simply giving consumers what they want, and using new technology to keep making larger cars that manage to fit within average mileage expectations.  As Knittle notes, “Firms are going to give consumers what they want, and if gas prices are low, consumers are going to want big, fast cars,” and that the only solution must come in the form of economic incentives, mainly that, “The right starting point is a gas tax.”