Tai Stillwater, a transportation researcher at the University of California, Davis, is a fan of the eco-driving movement known as hypermiling, in which drivers compete to squeeze amazing fuel economy from their cars. He doesn't recommend resorting to such extreme hypermiling measures as drafting behind 18-wheelers, removing the backseat to save weight, or zooming around corners without braking, to avoid losing momentum. But here's what you can do:
1. Slow down: Driving 5 miles over 60 miles per hour is like paying 29 cents extra for every gallon of gas you burn. That premium goes up as your speed increases.
2. Be a smooth operator: According to the Environmental Protection Agency, drivers who accelerate moderately and evenly and go easy on the brakes (coasting whenever possible) can save $1 or more per gallon.
3. Lose the rack: Add-ons such as flags, bike carriers, and luggage racks undermine your car's aerodynamics. (Close the windows, too, particularly at highway speeds.)
4. Chuck the junk in the trunk: Extra weight makes the engine work harder — so resist the urge to store your bowling balls in the backseat.
5. Kill the engine: Fifteen minutes of idling can burn a quarter of a gallon of gasoline, especially if the AC is blasting.
Michigan native Joe Eaton has been wrenching on old cars for two decades; he now writes from Baltimore.