Bengt halvorson april 15 2015 comment now.
Most fuel efficient roof box.
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.
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.
For comparison the additional fuel consumption caused by roof racks is about six times larger than anticipated fuel savings from fuel cell vehicles and 40 percent of anticipated fuel savings.
If fuel consumption is a concern invest in a streamlined box which will cut through the air more efficiently.
A former rolls royce aircraft engineer was hired to take yakima s racks to the next level and we have him to thank for the wispbar s wind cheating aerofoil wing profile.
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.
Off the showroom floor the regal tourx gets 21 miles per gallon in the city and 29 mpg highway for a combined fuel economy of 24 mpg.
Roof boxes fix to your roof racks either with a basic u bolt system or a claw style attachment.
The box has tapers to a point and employs diamond textured aero skin to help it slice through the air and protect vehicle fuel economy.
The control test the tourx without roof rails.
Keep in mind that your car uses more fuel when it has a roof box attached our test car used 12 1 more fuel with the roof box fitted than without.
The claw attachments make it easier and quicker to mount and remove the box.
But if you.