When transporting equipment short or long distance, it can be useful to use a roof rack or roof bars to free up space in the car. Inevitably, this will have an effect on the vehicle’s performance, regardless of the cargo’s weight.
In this guide, we will take a look at how a roof rack affects your car and why. For a wide range of roof racks suitable for your particular car, check out our selection over at Euro Car Parts.
Fuel Consumption
One of the first effects a roof rack can have is on fuel consumption. As you apply weight to the top of the car, the engine has to work harder to keep accelerating, resulting in more fuel being used.
This is also a result of increased drag. Roof racks on their own will apply a small amount of drag and increase your car’s wind resistance, but this will concurrently rise as more items are added to the roof rack. The more there is attached to the roof rack, or if travelling with a large item such as a bike or roof box, the harder your car’s fuel economy can be affected.
Roof racks are useful if regularly transporting items, so it is good practise to remember to remove them when not in use. This can help lower your car’s increased fuel consumption by only using them when needed.
Handling
Heavy loads on a roof rack can impact how your car handles when driving. This is caused by a shift in the vehicle’s centre of gravity as wind hits the attached cargo and makes the car less aerodynamic. The subsequent effect is increased difficulty when steering.
Larger, wider loads will have a greater impact on your car’s wind resistance, so it is advisable to consider this if transporting something during windy days. Modern roof racks are able to redistribute the weight applied to them evenly, helping minimise the change in centre of gravity.
Noise
Another effect of using a roof rack is noise. Many racks are built to be aerodynamic and so any noise produced is minimal, but a whistling sound can occur as the rack bars cut through the air; this is called the Aeolian Noise.
The circumstances for this sound to be created are quite rare however, so this shouldn’t be a huge factor when purchasing a roof rack.
Height
This is a natural one to consider when adding items to your roof rack. Wherever you are travelling, your car’s height will increase as the load does, so it is important to take this into account if travelling under low bridges or entering car parks.
There are several types of roof rack and bar to consider when transporting cargo. For a detailed and easy-to-read breakdown, check out our guide on the styles of roof rack available and how to fit them.