Does a Roof Rack Decrease Gas Mileage? 

Last Updated on February 6, 2023 by Will Sabel

Roof racks are a fantastic addition to any car as it provides more storage option to carry your items or luggage. But does a roof rack decrease gas mileage?

The difference in gas mileage due to roof rack depends on what you are transporting or carrying. If your roof rack is empty, it will cause the car to move faster with efficiency and decrease gas mileage. However, oversized items on the roof will slow down the speed and require more engine pressure and gas. 

So, do roof racks increase fuel consumption? To find out more about does a roof rack increases fuel consumption or if the addition of roof racks decreases gas mileage, read on ahead.

Roof rack impacts on gas mileage

Roof Rack’s Impact On Fuel Consumption

A roof rack could significantly increase your mileage and gas consumption or decrease it notably. Even empty roof racks could cause a change in your mileage which is why it is essential to be aware of what you carry to minimize your expenses. A few factors that affect your gas mileage are mentioned below – 

Roof Racks Affect on Mileage

A study showed that an Altima driving at 65 miles per hour with nothing added on the roof had a 48mpg. Whereas, a sedan driving at the same speed with the addition of a roof rack only differed quite a lot from the Altima. The mileage on the sedan dropped by 11% or 5mpg only by the addition of the roof racks. The addition of the roof rack and the carrier totaled a whopping 19% or 9mpg. 

With higher drag force on your vehicle, you will eventually find that roof racks decrease the aerodynamics of your car as the frontal area of impact for headwind also increases. 

The Aerodynamic Shape Promotes Drag Force

The aerodynamics of a vehicle can not be changed or improved due to the roof racks. The air resistance is inevitably increased when you add additionally to the exterior of the car. The resistance creates more drag force and more pressure on the engine. Which subsequently means more fuel consumption.

However, this is only the case when you have oversized items on the roof racks. Since the aerodynamic shape makes it easier for the vehicle to move ease, it does not overpack the roof rack will increase fuel consumption. 

Difference With Or Without Roof Racks 

Even though roof rack racks are beneficial, a question remains – does empty roof rack affect gas mileage? 

The answer to that is, yes, even empty roof racks can impact your expenses. Even though you might not be carrying anything on the roof of your car, empty roof racks and their aerodynamic shape lead to minimizing wind resistance and promoting more driving speed. 

However, with a removed roof rack, you will be able to see an evident change in fuel consumption as there is nothing additional on the exterior of your car. This means there is nothing that could cause any resistance to the wind and subsequently lead to lesser fuel consumption and minimum pressure on the engine. 

Bottom Line

Roof racks can be beneficial for carrying heavy luggage or items that otherwise won’t fit inside the car. However, even though these racks make it convenient to accommodate the inside of the vehicle, they can cause a significant difference in fuel consumption and gas mileage. The luggage acts as a wind barrier and increases air resistance. 

Increased air resistance causes your car to slow down and requires more effort from the engine. Therefore, does a roof rack decrease gas mileage? – it depends on what it is you are carrying. Although, removing the roof racks ultimately can reduce fuel consumption and increase gas mileage. 

Author: Will Sabel

Will Sabel is an avid car enthusiast. When he's not writing for RidersWant, you'll find him cruising the country in a new car. People are always wondering how many cars he has!

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