Roof Rack Gas Mileage

Drag coefficient increases by speed squared.

Roof rack gas mileage.

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. The control test the tourx without roof rails. 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. 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.

Let s say that you drive 15 000 miles per year gas is 2 50 gal and your gets 25 mpg. Berkeley lab says that roof racks cause as much as a 25 percent loss in fuel economy and accounted for almost 1 percent of national consumption in 2015. Your fuel cost is ten cents mile or 1 500 year. Some drivers may see their gas mileage drop by as much as 20 percent depending on vehicle type and type of roof rack.

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. Mileage went from 41 mpg at 65 mph to 40 mpg. 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.