How Does a Roof Rack Really Affect Your Car? Fuel, Noise, Wear & More Explained

Key Highlights

• Impacts Beyond Fuel: Roof racks affect cars in multiple ways, not just fuel economy. This includes wind noise, vehicle handling, and potential wear and tear.

• Reduced Fuel Economy: Confirms MPG loss (5-15% empty, 20-25% loaded) due to aerodynamic drag, influenced by speed, rack design, vehicle type, and load.

• Increased Wind Noise & Drag: Racks disrupt airflow, creating turbulence and audible wind noise (humming/whistling), especially at higher speeds.

• Potential for Wear and Tear: Poor installation or overloading can cause paint damage, roof dents, and strain on the vehicle's shocks and brakes.

• Mitigation Strategies are Crucial: Negative impacts can be lessened by removing racks when not in use, ensuring proper installation, distributing weight evenly, adhering to weight limits, driving slower, and choosing aerodynamic designs.

• Balancing Act: Roof racks offer significant utility but come with drawbacks; smart usage and maintenance are key to minimizing negative effects.

Overview

Our first thought when embarking on an adventurous trip is to install a roof rack for the extra luggage. Isn’t it true? But do you know how does a Roof Rack really affects your Car? Roof racks, though, are very helpful, but they have some setbacks, including more fuel consumption, wind noise, or some scratches here and there. 

Many roof rack owners wonder if this extra luggage holder is costing them more money besides the roof rack’s cost. You might be concerned about the drop in mileage of your car, difficulty in handling the vehicle, or long-term damage caused by the rack. When paired with conflicting information on the internet, these concerns will make you worry.

So, this article is right here to guide you. With factual information and experts’ reviews, we have compiled all the answers to your worrisome questions. So, let’s find out how to pair the convenience of the roof rack with the efficiency of your vehicle.

The Purpose of Roof Racks & The Core Question

Roof racks provide ease and convenience to carry extra luggage around, whether it be cargo boxes, roof top tents or heavy kayaks and skis. Roof racks turn your simple vehicle into a luggage loader. 

But, the question arises: what are the drawbacks of adding a roof rack to your car? Or what are the setbacks of carrying heavy things around?

Although people are well aware of the benefits of a roof rack, many are unaware of the physical drawbacks that come with it. 

Impact on Fuel Economy:

The roof rack and the luggage on top of it directly impact the fuel economy. It increases the aerodynamic drag of your vehicle, which is the resistance a car creates when it pushes against the air. The more the air resistance, the more the engine needs to work harder, hence, more fuel consumption. 

• A roof rack that is empty affects 5-15% of the fuel cost, depending on the style and type of your vehicle.

• A roof rack fully loaded affects 20-25% of the fuel cost. 

Key Elements Impacting the Fuel Economy:

• Speed: The faster you go, the more air drag, hence, more energy is required. Fuel consumption increases with the increase in speed.

• Roof Rack Design: The shape of the rack also influences the fuel economy (Aluminum vs. Steel design). Sleek and streamlined racks cost less energy than high, market-bought racks.

• Vehicle Type: SUVs impact the fuel economy lesser than sedans.

• Empty or Loaded: Empty racks also cause an increase in fuel economy. And when it is loaded, the fuel economy further increases.

Expert Tip: When the rack is not in use, remove it. It will have a significant impact on the fuel economy of your car.

Environmental Impact: The more energy is consumed, the more CO₂ is produced, which is not healthy for the environment.

Effect on Aerodynamics and Wind Noise

Roof racks interrupt the normal airflow around the car. It mainly depends on the design and layout of the rack. 

• The once sleek roof of your car is now strapped with a grilly structure of a roof rack. This causes more turbulence.

• The air passing through the structures of a roof rack creates whistling and humming noises.

• The noise and aerodynamics are also affected by the speed of the car and the luggage on top of it.

Influence on Vehicle Handling and Performance

The centre of gravity of your car increases with the increase in luggage on top of your vehicle. It makes handling and performance of the car rather tricky. 

• The weight affects the speed of the car. More speed is required to push a car heavy with luggage. 

• Brakes are to be applied earlier than the normal distance, as the luggage affects the braking system of the car.

• The car is to be handled carefully when taking a turn. 

Expert Tip: Make sure to evenly distribute the luggage on the roof rack. Be more careful when driving fast or when on a highway. Also, check the weight-holding capacity of your vehicle. Be sure to keep the luggage under the minimum weight limit in case you are not well-trained to drive with a loaded vehicle.

Potential Vehicle Wear and Tear

Attaching a roof rack can also cause potential wear and tear to your vehicle, especially when the car is overloaded or the roof rack system is poorly installed. It can have the following effects on your vehicle:

• Paint Damage: Dragging, building up of dirt, shifting mounts, or vibrations can cause damage to the vehicle’ paint.

• Dents: When the car is continuously overloaded, it can lead to dents in the roof.

• Shocks and Brakes: Carrying heavy luggage, mainly on rough terrain, can impact the shocks and braking system of the car.

Expert Tip: Make sure to clean the roof under the rack regularly. Check the tightness of bolts and hinges before loading the luggage. 

Tips for Minimizing Negative Impacts

Now that you are well aware of the potential harms that may be caused to your vehicle while using a roof rack, the following is a breakdown of some measures that can ensure the safety of your vehicle and rack: