Roof Rack Gas Mileage

So it varies depending on the vehicle on the rack and on the driving highway or city but it s at least five percent and probably a lot more.

Roof rack gas mileage. Some drivers may see their gas mileage drop by as much as 20 percent depending on vehicle type and type of roof rack. The empty roof rack had a nearly 2 percent impact on fuel economy which translates to a little more than three quarters of a gallon of gas. The roof rack mpg experiment. Off the showroom floor the regal tourx gets 21 miles per gallon in the city and 29 mpg highway for a combined fuel economy of 24 mpg.

Drag coefficient increases by speed squared. Let s say that you drive 15 000 miles per year gas is 2 50 gal and your gets 25 mpg. The control test the tourx without roof rails. He found that compared to the baseline of no roof rack the empty rack reduced his mpg by 12 7 and the roof rack with a bicycle reduced it by a whooping 27 3.

He compared the gas mileage of his car at 54 7 mph 88 kph with 1 no roof racks 2 an empty roof rack and 3 a mountain bike on the roof rack. Generally adding a loaded roof rack to your car will lower your gas mileage by at least 10 percent. Mileage went from 41 mpg at 65 mph to 40 mpg.