Roof Box Fuel Efficiency

Yes more than you think.

Roof box fuel efficiency.

Adding any rooftop carrier cargo box or ski rack to your car significantly cuts your highway mileage all the time it. As the british magazine what car. Recently found adding properly fitted roof boxes and a modest amount of cargo to a couple of compact family models decreased their effective gas mileage by up to. The roof rack mpg experiment 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.

Their study was published recently in the. 5 6 l 100 km 42 mpg roof rack with thule dynamic 800 aerodynamic cargo box. They found that in 2015 roof racks nationwide were responsible for 0 8 percent of light duty vehicle fuel consumption or 100 million gallons of gasoline. 6 0 l 100 km 39 mpg thus the cargo box on the roof increased fuel consumption by about 5 compared to the baseline.

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. It s impossible to give an exact figure because it depends on so many factors but britain s biggest roof box manufacturer thule states that your mpg is unlikely to decrease by more than 5.