Mileage went from 41 mpg at 65 mph to 40 mpg.
Roof pod fuel economy.
A control test was first completed with the roof of a petrol powered natural aspirated subaru forester unburdened by any racks or cargo only the factory installed roof rails remained.
Adding a roof box means your car has to carve a bigger hole in the air which requires burning more fuel so your mpg will suffer.
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.
That 100km run chewed up 6 46 litres of petrol and was our baseline number.
Mileage went from 41 mpg at 65 mph to 40 mpg.
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.
30 5mpg astra s baseline fuel economy 30 4mpg two front windows a third open 30 3mpg roof bars and laden roofbox 30 2mpg two front windows totally open 29 7mpg four tyres down to 20psi.
Their study was published recently in the journal energy policy in a paper titled fuel consumption impacts of auto roof racks.
Their study was published recently in the.
The control test the tourx without roof rails.
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.
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.
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.
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.
If you follow our coverage on fuel efficiency you know that real world mileage numbers don t always measure up to the official epa ratings.
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.