How Much Mpg Do You Lose With A Roof Rack

Disrupting airflow over the roof and causing turbulence has more of an effect the faster you drive.

How much mpg do you lose with a 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. It caused a whopping 34 percent drop in fuel economy or 10 mpg. And since air resistance increases exponentially with speed the difference would have been even bigger at 70 mph many people drive at that speed. Some drivers may see their gas mileage drop by as much as 20 percent depending on vehicle type and type of roof rack.

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. 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. 6 0 l 100 km 39 mpg thus the cargo box on the roof increased fuel consumption by about 5 compared to the baseline. 5 9 l 100 km 40 mpg roof mounted thule xtender 739 ski carrier with skis.

If you must travel with a loaded roof rack try to choose the most aerodynamic roof rack you can.