Mileage went from 41 mpg at 65 mph to 40 mpg.
Roof rack gas mileage impact.
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.
A close second was the kayak with 28 percent or a change.
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.
The other great thing with the thule system is that it takes literally 2 minutes to get the box off and maybe 5 10 mins to take the bars off each time so it really isnt that much of a hastle if you want to save on gas when you re not using it.
A drop of 7 percent may not sound like much but it adds up over time.
I ll justify these numbers below.
Adding an empty roof rack to a vehicle can drop the gas mileage by about 7 percent.
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 gear with the most impact were the dual mountain bikes strapped to the roof which impacted the fuel economy by 31 percent or 9 mpg.
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.
This means that adding an empty roof rack to a car that usually gets 35 mpg will drop the gas mileage to 32 5 mpg.
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.
Unfortunately even an empty roof rack will affect mileage.