Does Your Car’s Roof Rack Affect Its Gas Mileage?

Do you need to bring a lot of things or a single large item that just won’t fit in your car’s trunk, your SUV’s rear cargo space, or even your truck’s bed? You might need a roof rack. The rack will allow you to carry more things with you safely and securely.

However, there’s no such thing as a free lunch. While the roof rack increases cargo capacity, it may also affect your vehicle’s performance. Read on to learn if and how the roof rack affects your car’s gas mileage.

Does the Roof Rack Affect the Gas Mileage of Your Car?

Yes, the roof rack increases fuel consumption and reduces fuel efficiency. However, the extent of the effects can vary according to different factors. Some roof racks are light and small, so they have minimal effect on fuel efficiency. Others take up considerable space and use sturdy but heavy materials, which increase their effects. 

How Much Does a Roof Rack Affect Fuel Economy?

A 2016 study by Yuche Chen and Alan Meier showed that a roof rack increases the amount of fuel consumed by the vehicle. Passenger cars with roof racks can use up to 25% more fuel, while trucks can burn as much as 11.7% additional gas or diesel. The percentages vary according to factors like the roof rack being loaded or unloaded and if the vehicle was driving on urban roads or the highway.

What Is a Roof Rack?

So, what is a roof rack? It’s a storage rack mounted on your vehicle’s roof. The roof rack can accommodate multiple items, large objects, and containers like bags, boxes, and carriers.

Roof racks are a recurring sight on cars and trucks in the U.S. When you come across a rack, it usually carries gear for outdoor events. Depending on the rack and the vehicle, it can hold bicycles, canoes, kayaks, luggage, and ski equipment.

How Does a Roof Rack Reduce Gas Mileage?

There are several ways by which a roof rack can affect the gas mileage of your vehicle. They are the following:

Airflow and Aerodynamic Drag

The roof rack interferes with the airflow around your vehicle by expanding the surface area in contact with air. It increases aerodynamic drag, the force your car encounters while moving through air. This drag slows down your vehicle, requiring more horsepower to overcome. That means burning more fuel to meet the increased engine load.

Car manufacturers often design their vehicle models with aerodynamic performance in mind. Even bulky vehicles like trucks and vans receive sleek surfaces to minimize drag. Installing a roof rack on a car or truck that doesn’t come standard with one disrupts that carefully calculated silhouette, increasing aerodynamic drag and forcing the engine to burn more fuel to overcome the resistance.

The weather also interacts with the roof rack in ways that reduce your vehicle’s gas mileage. Driving into headwinds or encountering crosswinds increases wind resistance. (Conversely, a tailwind pushing your car or truck from behind might improve fuel efficiency.)

Air also grows more dense at lower temperatures. Denser air imposes more aerodynamic drag on vehicles moving through it. Again, the engine must work harder and consume more fuel.

Weight

The roof rack doesn’t only take up space on the roof. It also makes your vehicle heavier, which may have a significant impact on fuel economy. Your vehicle must compensate for the extra weight by burning more fuel to carry the heavier load. If the rack has a heavy load, it will impose an even heavier burden.

Some manufacturers reduce the weight of their roof racks through various ways, such as making their products from light yet strong materials and engineering hollow but sturdy parts. However, the typical rack remains a hefty accessory.

How to Improve Gas Mileage on Vehicles with a Roof Rack

You can restore your vehicle’s original fuel economy by removing the roof rack when it isn’t needed. Uninstalling the accessory reduces your vehicle’s weight and improves its aerodynamic profile. Removing and installing the part does take some time and will require you to exert yourself, but it also saves you fuel.

Plan ahead if you intend to use the roof rack on your vehicle. Install the accessory on your car or truck on the day before you expect to pack your gear. Doing so minimizes the time you spend driving with an empty roof rack.

How Much Does a Roof Rack Cost?

Are you set on getting a roof rack for your vehicle or need to replace an old one? A new roof rack can set you back by anywhere between $160 and $2,800.

While a roof rack does reduce your vehicle’s gas mileage, its benefits might outweigh its drawbacks in certain scenarios. The decision to install or remove the accessory ultimately depends on you. If the convenience of carrying more cargo or larger items offsets the reduction in gas mileage, go ahead and install a roof rack on your vehicle.

Getting Your Hands on a Roof Rack

Roof racks can be a little pricey because they’re designed to support all manners of heavy cargo without taking up too much space. On the bright side, you can get your hands on a durable roof yet affordable rack with the help of CarParts.com.

Our collection of auto parts is carefully vetted by a team of professionals to guarantee both quality and durability. You can get your hands on a new roof rack that’s built to last by browsing our catalog. All you need to do is visit our website or download our mobile app.

Just be sure to input the necessary details like the year, make, model, and engine of your vehicle. This way, you can find roof racks that are compatible with your vehicle. After you’ve placed your order, you can expect to receive it within a matter of days.

Spare yourself some time and trouble by shopping for your new roof rack online.