Vehicles are tested at a top speed of 80 mph in order to calculate the highway mpg estimates.

EPA utilizes five test cycles to represent real-world driving conditions. While it’s true that the test cycle historically labeled as the “highway” test has a top speed of 60 mph, this test is currently meant to represent driving on lower speed highways as well as rural and suburban driving. EPA’s highway mpg estimates are primarily derived from a separate “high speed” test cycle, which has a top speed of 80 mph. The remaining three tests are designed to simulate stop-and-go city driving, high air conditioning use, and driving in cold temperatures. For more information on the five test cycles and how EPA calculates its mpg estimates, go to epa.gov/fueleconomy.