To make the numbers in the Gas Mileage Guide more useful for consumers, EPA adjusts these laboratory test results to account for the difference between controlled laboratory conditions and actual driving on the road. The laboratory fuel economy results are adjusted downward to arrive at the estimates in this booklet and on the labels seen on new cars, light duty trucks, and vans. The city estimate is lowered by 10 percent and the highway estimate by 22 percent from the laboratory test results. Experience has proven that these adjustments make the mileage estimates in this Guide correspond more closely to the actual fuel economy realized by the average driver. No test can simulate all possible combinations of conditions, climate, driver behavior and car care habits.
Actual mileage depends on how, when, and where the vehicle is driven.
EPA has found that the mpg obtained by most drivers will be within a few mpg of the estimates in this booklet. The car will run more smoothly and efficiently. Keep tires inflated to the manufacturer's recommended maximum pressure. Traveling at higher speeds lowers fuel economy. Traveling at 65 mph instead of 55 mph lowers fuel economy over 15 percent.