U.S. Department of Energy - Energy Efficiency and Renewable Energy

Vehicle Technologies Office

Fact #591: October 5, 2009
Consumer Reports Tests Vehicle Fuel Economy by Speed

Seven vehicles were tested by Consumer Reports recently to determine the fuel economy of the vehicles at a given speed. For these vehicles, the decline in fuel economy from a speed of 55 miles per hour (mph) to 75 mph was between 20% and 30%. The Honda Insight, which is a hybrid vehicle, had the greatest fuel economy decline (30%) from 55 to 75 mph, but the Toyota RAV4 had the greatest fuel economy decline from 55 to 65 mph (15%).

Fuel Economy by Vehicle Speed for Seven Tested Vehicles
Graph showing the change in fuel economy for various vehicles when they were driven at speeds from 55 mph to 65 mph and 55 mph to 75 mph. The decline in fuel economy from the lower to the higher speed was between 20% and 30%. For more detailed information, see the table below.

Supporting Information

Fuel Economy by Vehicle Speed
Make and model Engine 55 mph 65 mph 75 mph Change from 55 to 65 mph Change from 55 to 75 mph
Acura TSX 2.4 liter, 4 cylinder 39.9 35.5 30.7 -11% -23%
Honda Insight 1.3 liter, 4 cylinder 51.9 44.8 36.5 -14% -30%
Lexus RX350 3.5 liter, V6 30.9 27.4 23.0 -11% -26%
Mercury Mountaineer 4.6 liter, V8 23.8 21.2 17.8 -11% -25%
Toyota Camry 2.5 liter, 4 cylinder 40.3 34.9 29.8 -13% -26%
Toyta RAV4 2.5 liter, 4 cylinder 34.6 29.3 25.9 -15% -25%
Toyota Yaris 1.5 liter, 4 cylinder 42.5 37.9 34.0 -11% -20%

Source: Consumer Reports, "Tested Speed vs. Fuel Economy," September 9, 2009. (Links to Consumer Reports blog.)

 

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