How Much Mpg Do You Lose With A Roof Rack

Roof rack with thule dynamic 800 aerodynamic cargo box.

How much mpg do you lose with a roof rack. 6 0 l 100 km 39 mpg thus the cargo box on the roof increased fuel consumption by about 5 compared to the baseline. This editor many years ago in a move across the country to oregon from michigan found that the highway mileage of a four cylinder accord dropped from more than 40 mpg down to 32 mpg with a. Some drivers may see their gas mileage drop by as much as 20 percent depending on vehicle type and type of roof rack. Depending on design and whether you have a deflector on the front these have been shown to reduce gas mileage by 10 15 even without anything on them.

Disrupting airflow over the roof and causing turbulence has more of an effect the faster you drive. So if your car usually gets 30 mpg on the highway and you add a full roof rack your highway gas mileage will drop to 24 27 mpg. 5 9 l 100 km 40 mpg roof mounted thule xtender 739 ski carrier with skis. And since air resistance increases exponentially with speed the difference would have been even bigger at 70 mph many people drive at that speed.

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.