How Much Do Roof Racks Affect Gas Mileage

As you get ready to hit the road this summer with the kids loaded inside and the bikes strapped to the roof of your car you may want to stop and consider that the roof rack on your car may be costing you as much as 25 percent more in gas.

How much do roof racks affect gas mileage. Let s say that you drive 15 000 miles per year gas is 2 50 gal and your gets 25 mpg. Your fuel cost is ten cents mile or 1 500 year. Using a 2013 honda accord and data provided by consumer reports an empty roof rack will increase the amount you spend on gas by 12 compared to no rack at all assuming highway speeds. Beyond that the two items tested with the least impact on gas mileage were the paddle board and thule luggage carrier both of which caused about a 19 percent decrease in fuel economy or 5 5.

Even though they might look like they cut through the wind they could be introducing some mileage robbing turbulence. I am somewhat suspicious of this first figure but it s possible. A two bike rack with wind deflector will increase your gasoline costs by 36. Drag coefficient increases by speed squared.

The same of course applies to roof racks and other cargo accessories. Mileage went from 41 mpg at 65 mph to 40 mpg. 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. A roof rack with bikes attached greatly decreases gas mileage.

Gas mileage may drop by as much as 30 percent. How much does a bike roof rack affect gas mileage. A bike roof rack with bikes may make the largest impact on gas mileage. If you re traveling with your bikes attached to your roof you ll have to stop more often for.