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.
Fuel economy of roof rack vs luggage box.
Aerodynamics is the study of force and how an object moves through the air.
Is a fancy low profile ski rack the answer or could a cargo box get me better fuel economy.
40 mpg roof mounted thule xtender 739 ski carrier with skis.
The more aerodynamic a car is the better the gas mileage it will have.
On my maxima i was able to get 25mpg with no rack at all when i added a yakima fat cat 6 loaded with skis i got approx 20mpg.
Mileage went from 41 mpg at 65 mph to 40 mpg.
This includes a roof rack bike rack luggage rack pair of bikes or anything else you may strap to your vehicle.
I have personally tried both options on two different vehicles and i can say positively a cargo box gives you more mpg s.
5 9 l 100 km approx.
42 mpg roof rack with thule dynamic 800 aerodynamic cargo box.
6 0 l 100 km approx.
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.
Adding any rooftop carrier cargo box or ski rack doesn t come free.