You know that driving at 75 mph rather than 55 wastes gas, but how much? We did the math, driving a steady 55, 65, and 75 mph in a Honda Accord, a Toyota RAV4, and three versions of a Ford Fusion. The penalty for speeding, even in those relatively fuel efficient cars: a loss of up to 14 mpg.
True, driving 200 miles at 75 instead of 55 shaves an hour off your trip. But in the cars we used, it also wastes 1 to 2 gallons and costs about $5 to $7. For every thousand miles at 75 mph, you're increasing carbon footprint by 7 to 10 gallons and throwing away about $30.
Need more motivation? High speeds increase the likelihood of a crash and slash the odds of surviving one, says the Insurance Institute for Highway Safety.
Other gas-saving tips. Drive smoothly when possible, avoiding hard acceleration and hard braking. Combine short trips to avoid driving with a cold engine, and keep tires properly inflated. Turn the car off if it will be idling for more than about 30 seconds.
Model 55 mph 65 mph 75 mph mpg drop 55-75 Honda Accord LX 4-cyl. 49 mpg 42 mpg 35 mpg 29% Ford Fusion Hybrid 49 41 36 27 Ford Fusion 1.6 4-cyl. 41 36 30 27 Ford Fusion Titanium 2.0 4-cyl. 41 34 28 32 Toyota RAV4 37 33 27 27
