How Will a Roof Rack Affect Your Car?

A roof rack adds more wind resistance, adds extra weight, and changes your car’s centre of gravity. Each of these has a different impact on how your vehicle handles and how efficiently it moves:

Wind noise

One of the first things drivers notice after installing a roof rack is the noise. Roof racks obstruct the smooth flow of air across your roof. This creates turbulence and makes those whistling or humming sounds that many people find annoying.

You can get roof racks designed to cut wind resistance and noise, but even the smoothest, most aerodynamic roof rack will still increase air resistance and generate extra noise.

Fuel efficiency

More wind resistance means that your vehicle has to work harder to overcome aerodynamic drag. This means reduced fuel efficiency, especially as you hit higher speeds and increase drag.

If you're carrying bulky items like bikes or cargo boxes, wind resistance (and therefore fuel consumption) increases further. If you're driving an electric vehicle, you won't get as much mileage per charge, while drivers of petrol/diesel vehicles will end up paying more at the pump.

Vehicle handling and stability

Even the lightest roof racks add extra weight and height to your vehicle, which affects its handling. For example, more weight on the roof raises your car's centre of gravity, making it more prone to body roll when taking corners. While it's unusual for a car to flip due to a roof rack, it does make a noticeable difference to general vehicle stability.

Your steering may also feel less responsive when you add a roof rack. If you are carrying heavy loads or haven't distributed the weight of the load evenly enough, your car may lean further than usual when you spin the wheel. This can take some getting used to.

Weight capacity and stress on the car

Every car has a maximum roof load capacity. If you overload your roof, you can strain its structural integrity, which could lead to costly repairs to mounting points and suspension. Too much weight could also wear down your tyres and brakes.

Check your vehicle's manual and the rack manufacturer’s guidance to work out your vehicle's roof load limit, and don't exceed that limit.

Paint and roof damage

Roof racks are hefty pieces of equipment, and can damage the roof surface and paintwork causing dents or scratches to your car if you don't install them properly. Ideally, you should thoroughly clean both your vehicle and the rack's mounting points before installation, as dirt and moisture trapped beneath the rack can corrode your roof over time.

Accessibility and convenience

On the plus side, a roof rack makes it much easier to carry awkward and oversized cargo. However, the added height can make loading and unloading items challenging. Some roof rack models come with slide-out or fold-down features to improve access, so if you are short or your car is tall, it may be worth considering this when shopping for roof racks.

If all the above sounds negative, don't worry. Many people find that the practicality, comfort, and convenience benefits of roof racks easily outweigh potential drawbacks.

Increased cargo space

Roof racks allow drivers to transport luggage, camping gear, sports equipment, bikes, tools, etc, without sacrificing space inside the car. Families, tradespeople, and anyone who needs extra storage space can benefit from increased cargo capacity.

Transport versatility

Roof racks can turn a regular car into a multipurpose vehicle. A good roof rack can hold everything from cargo boxes to surfboards to work ladders. This adds a level of versatility that's valuable for a whole range of people and purposes.

Many roof racks have modular systems, which means you can easily swap attachments depending on what you need to carry.

Interior comfort

Travelling in a car while surrounded by boxes, cases, and equipment isn't ideal. By storing cargo on a roof rack, passengers and drivers within the car get a much more comfortable ride.

Perhaps more importantly, storing heavy and oversized items on the roof is also safer. If you have to brake suddenly, heavy cargo won't tumble into you or your passengers, and it won’t obstruct your visibility while you’re driving.

Resale appeal

You may assume that, with all its impacts upon a car's performance, a roof rack would reduce resale value. In fact, the opposite is often true. A well-installed, well-maintained roof rack can add to your vehicle's resale value.

Buyers who want the practicality and extra cargo space of a roof rack often appreciate vehicles that come with them ready-fitted. It saves them the expense and hassle of purchasing and installing a rack themselves. However, a poorly-installed or badly maintained roof rack isn't as appealing, and may reduce your car's value.

Roof racks are popular and practical accessories that can transform any car into a versatile, multi-purpose vehicle. However, the convenience and practicality of a roof rack do come with trade-offs in your car's performance. From increased fuel consumption to wind noise, drivers with road racks frequently report changes in their car's handling and efficiency.

You can reduce the impact of a roof rack with careful installation, maintenance, and loading. So, if you are prepared to look after it, you may well find that the convenience and flexibility of a roof rack outweighs its drawbacks.

For more tips on car maintenance and getting the best performance out of your vehicle, check out our handy motoring guides.