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Fuel-Saving Speed

October 11, 2005

With prices at the pump so high, one listener wants to know whether driving slower saves gas–and money.


The best speed for your wallet. I’m Bob Hirshon and this is Science Update.

Hoping to save some gas money on a road trip, Science Update producer-on-leave Corinna Wu called to ask if there is an ideal speed for gas mileage.

We asked Oak Ridge National Laboratory engineer Brian West. He says that in general, the optimum speed is around 50 to 65 miles per hour. Going slower, your engine runs less efficiently, and going faster, the drag from the wind offsets the engine power. But he cautions that other factors weigh in, and that simple solutions may backfire.

BRIAN WEST (Oak Ridge National Laboratory):
If we just have a knee-jerk reaction and lower speed limits everywhere, we could cause gridlock then and fuel economy would actually go down.

If you’ve got a science question, cut the gridlock and call us at 1-800-why-isit. If we use it on the show you’ll get a Science Update mug. I’m Bob Hirshon, for AAAS, the science society.