This article delves into how a heavy load on your roof rack can impact your car’s handling and performance on the road.
Loading up the roof rack is a great way to free up space inside your car for long trips.
How Will a Heavy Load on Your Roof Rack?
Carrying a heavy load on a roof rack can reduce driving stability and increase wind resistance.
Securely fasten all items to the rack and use appropriate restraints.
Place heavier items low and towards the centre.
Key Points
- Can shift the centre of gravity and reduce stability
- Securely fasten all items to the rack
- Use restraints and place heavy items low and central
Our Opinion
In our expert opinion, roof racks can safely carry heavy loads if used correctly.
The key is securely fastening all items, using tie-downs and restraints, and loading heavier items low and centrally.
This maintains stability and handling.
Only use roof racks designed for your specific vehicle.
How a Heavy Roof Rack Load Affects Your Car’s Handling
Adding a heavy load to your roof rack can affect your car’s stability and road holding in a few key ways:
- Raises the centre of gravity – Loading heavy gear on the roof raises your car’s centre of gravity. This can make the vehicle more prone to rollovers and loss of control around corners.
- Changes in weight distribution – The extra weight up top shifts weight away from the wheels and tires, reducing traction. This is especially noticeable when braking.
- Increases body roll – With a raised centre of gravity, your car’s body will tilt or sway more through turns. Steering response can feel slower.
- Impacts aerodynamics – A loaded roof rack causes more wind resistance against your car. This decreases fuel economy and steady road handling.
The key is to evenly distribute the load, secure it properly, and not exceed your car’s roof weight limit. Drive slower than normal and allow extra stopping distance. Handling a car with a heavily loaded roof takes extra care and attention.
The Impact on Braking Distance
When your car’s roof rack is loaded down, the extra weight has a direct impact on braking distance. Here’s what happens:
- More weight means more momentum – All that weight up top means your car has more momentum when moving at any given speed. More momentum equals more stopping distance required.
- Weight shifts forward under braking – Braking forces the load to shift forward, reducing weight on the rear tires. This decreases rear grip and stability.
- Longer stopping times – With more weight to halt and less tire grip, your braking distances increase. It can take up to 25% longer to fully stop your car.
- Increased chance of dipping – Excessive front weight shift while braking can cause the front suspension to ‘dip’ down. This reduces steering control.
Driving with a heavily loaded roof rack requires earlier braking and more gradual stops. Always keep a safe following distance from other vehicles. Know that your car won’t brake as quickly or as stably until that roof rack is empty again.
Reduced Fuel Economy from Extra Weight
That heavy load up top will cost you at the fuel pump too. Here’s why:
- More weight strains the engine – Your engine has to work harder to accelerate and maintain speed with hundreds of extra pounds on board.
- More wind resistance – A bulky cargo box or oversized load creates more aerodynamic drag, requiring more effort from the engine.
- More rolling resistance – The additional weight presses down on the tires more, increasing friction between the tires and the road.
- More stops and starts – The longer braking distances make smooth stops tricky, leading to more gas-wasting stops and starts in traffic.
All that extra work can reduce fuel economy by up to 25%. So go easy on the accelerator and keep speeds moderate. Removing unneeded cargo and empty racks when not in use helps too. Just a few commonsense driving adjustments will keep your fuel economy impact low.
Potential Damage to Your Car’s Roof and Suspension
Loading up the roof with heavy gear can stress your car’s body and the suspension past shouldn’t be limited. Watch for these trouble signs:
- Sagging roof – Look for gaps at the doors and windows if the roof starts to droop.
- Creaking noises – Listen for creaks and groans from the roof and suspension when going over bumps.
- Difficult steering – Heavier front loads can make the steering wheel harder to turn.
- Bottoming out – Scrapes underneath mean the shocks are maxed out.
- Roof rack damage – Cracked plastic and bent bars signal overload.
Prevent damage by not exceeding the roof weight limit in your owner’s manual. Distribute loads evenly and tie them down securely. Consider a roof reinforcement kit if heavy loads are frequent. And adjust driving habits to take it slower over bumps and turns. With care, your car can handle the extra burden.
Safety Risks of an Overloaded Roof Rack
An overloaded roof rack doesn’t just damage your car – it can put you and others in harm’s way. Some key risks to be aware of:
- Impaired handling – Excess weight up top raises the centre of gravity, making your car less stable and harder to control.
- Longer braking distance – Heavier loads increase stopping distance, so allow extra room to slow down.
- Loose cargo – Improperly secured items can slide or fly off, endangering other motorists.
- Obstructed vision – Bulky loads can block your rearview, blind spots, and mirrors.
- Rollover risk – Top-heavy SUVs and trucks are more prone to tipping over with heavy roof loads.
Drive slowly and avoid sudden manoeuvres. Give yourself extra following distance. Take regular breaks to re-secure cargo. And be mindful of road conditions – windy days and curvy roads call for extra caution with roof loads.
FAQ
What is the roof rack on a car theory test?
Carrying a heavy load on a roof rack can reduce driving stability and increase wind resistance.
How much weight can a car roof support?
The car manual gives you a dynamic roof weight limit or roof load of 70kg.
How should a load be carried on your roof rack?
Any load on your roof rack should be fastened securely with a suitable restraint and placed in a secured roof box. This will keep the items safe and dry throughout your drive.
What are the disadvantages of loading the roof rack so high?
Loading heavy gear on the roof raises your car’s centre of gravity. This can make the vehicle more prone to rollovers and loss of control around corners.
Conclusion
Carrying a heavy load on a roof rack can reduce the stability of the vehicle by shifting its centre of gravity. It is important to securely attach any items carried on the roof to prevent them from sticking out. Fastening the load with a suitable restraint and placing it in a secured roof box will help maintain stability. Additionally, heavy loads on a roof rack can slightly improve fuel economy due to the car being lower to the ground. However, it is advised not to strain when loading the rack to avoid dropping and damaging the car’s roof. Carrying a heavy load on the roof can also increase wind resistance and noise. This can impact how the car handles while driving. To properly secure the load, ensure that you have the right roof rack for your car and that it is securely attached.
