Whether you're taking a student to university, visiting a DIY store or going on a road trip, fitting a lot of things into your car is challenging.
This is also how overloading happens. Every car comes with very specific weight limits that should not be exceeded.
Overloading is when you pack more weight into your car than it’s designed to carry. This causes strain on the tyres and can lead to problems such as tyre blowouts.
Overloading your car affects:
- The car's handling
- Braking
- The suspension system
- Overall stability
- Occupant safety
An overloaded car is difficult to control, especially in an emergency. Things sliding around or tipping when you brake, or turn can be dangerous. Before packing for your next trip, consult your car’s manual to find the maximum weight that it can safely hold.
Understanding vehicle overloading
Without you knowing it, you can easily overload a vehicle.
Let’s say you’ve planned a trip to take your child to university. The car is jam packed with their things and passengers. Your car is now holding more that its Maximum Authorised Mass (MAM). Overloading your car in this way puts immense strain on the tyres.
The MAM is the total maximum weight of your car and everything in it, including passengers. It can be found on the VIN plate, under the bonnet or in your handbook.
Here are some signs that your vehicle is overloaded:
- Visible sagging of the suspension where there is too much weight, which is usually in the back of the car
- Braking
- An underinflated or flattened tyre, which is your car telling you it’s been overloaded
- Unusual sounds from your suspension system and/or problems with handling
The dangers of overloading your car
Overloading your car is very dangerous and can lead to several problems.
Dangers of an overloaded car include:
- Throwing off your centre of gravity and reducing the stability of the vehicle
- Increasing the vehicle’s starting and stopping times – burning more fuel over time
- Impairing the vehicle’s handling and increasing its stopping distance
- Overloading will cost you more money on refuelling and upkeep because the car is being pushed beyond its limits
We provide 24/7 roadside assistance.
Who’s responsible if you overload a car and what are the legal or penalty implications?
Try to keep a clear view to the rear by not packing above the line of the seat backs.
If you’re tight on space think about using a roof-rack or roof-box. These are very useful for carrying lighter but bulky items like bedding and will leave more room inside the car.
Make sure passengers are safe and comfortable
In the UK, the responsibility for overloading a car lies with the driver of the car. It’s the driver's responsibility to ensure that the weight of the passengers and cargo is within the car's weight limit.
A car overloading penalty will normally consist of a fixed penalty fine of:
- £100 fine for less than 10% overloaded
- £200 for between 10 to 14% overloaded
- £300 for 15% overloaded and over, plus 3 points on your licence
For serious cases of overloading a vehicle over 30%, you could receive a court summons. The most severe punishment possible would be a 2-year prison sentence if found guilty of dangerous driving under the Road Traffic Act 1988.
You may also not be permitted to continue your journey till the weight has been reduced or risk having your vehicle impounded.
Not many people know this, but overloading your car with people or items can also invalidate your insurance policy.
How to tell if your car’s overloaded
If you’ve overloaded your car, there are a few key things to look out for. If you notice any of these issues, it may be better to reduce your load or hire a van to help move some of your items:
- Your vision is obscured – if there’s so much in your car that you’re unable to see around the vehicle or have a clear view of the mirrors, you’ve crammed too much in there
- Look at your suspension (how far away from the ground the body of your car is) and the shape of the wheel arches – if either of these looks drastically different after packing your items onto/into the car, then you’re likely to be overloaded
- Your handling is severely reduced – if you notice that your car is much less responsive (more difficult to turn, stop and start) then it’s likely to be over-encumbered
Does overloading a car damage it?
Driving with the occasional heavy load in your vehicle shouldn’t do permanent damage, but overloading a car consistently over time can cause many issues. For example, your engine, suspension, brakes and tyres will all be put through extra strain, shortening the lifespan of your car and resulting in big maintenance costs.
Our tips when loading a car
Don’t overload your car – it could be dangerous for yourself and others. See our expert tips below for a smooth journey:
Is your spare wheel still accessible?
If you've got a spare wheel, think about how you’ll get to it in an emergency.
- Using several soft bags rather than throwing things in loose will make it easier if you or one of our patrols has to fit the spare
Keep larger or heavier things low
Packing’s easier if you put bigger things in first and then pack smaller items around.
- Placing heavier objects first helps keep the centre of gravity lower which is better for handling
- Push heavy items like bottles or DIY materials tight up against the back of the rear seat. They’re less likely to burst through in a crash
Make sure passengers are safe and comfortable
If you have to fold seats to carry a large or awkward load, leave passengers and collect them later rather than take a chance by carrying them unrestrained.
- Fit child restraints first as this might be harder to do after you've packed everything else
- Try to leave plenty of room around children – stuff packed tight around them could make for an unhappy journey
- Keep a bag handy for things you might need during the journey
Make sure your line of vision is clear
Try to keep a clear view to the rear by not packing above the line of the seat backs.
If you’re tight on space think about using a roof-rack or roof-box. These are very useful for carrying lighter but bulky items like bedding and will leave more room inside the car.
Carrying heavy items
It’s important to make sure the combined weight of your passengers and cargo are within the car's weight limit to avoid putting additional strain on the tyres, suspension, and braking system.
Don't load anything over or past your parcel shelf / height of the rear seats as these can become a projectile in the event of a collision.
Overloading an axle
Overloading an axle means putting more weight on a car's axle than it’s designed to handle. When an axle is overloaded, it puts more strain on the car's suspension system, which can cause it to wear out faster or fail. Overloading an axle is considered a traffic violation, and you may be subject to a fine or have your car impounded until the excess weight is removed.
Overloading a car with passengers
If you must fold seats to carry a large or awkward load, leave passengers and collect them later rather than take a chance by carrying them unrestrained.
Cars are designed to transport passengers safely in a set number – typically one for every seat in the car. Most cars can accommodate the driver and up to 4 passengers, with 1 person in the front and 3 in the back. However, larger cars may have additional seats in the back and can carry up to 7 passengers.
Overloading a car with passengers can put everyone at risk and increase the chances of accidents and injuries.
How will a roof rack affect your car?
If you’re wondering what happens to the driving performance of an overloaded car, or what it’s like to drive with a heavy load on your roof rack, these are some of the things that you’ll encounter:
- Your centre of gravity will be affected – heavy loads can reduce the stability of your vehicle by shifting that centre away from what the vehicle manufacturer intended
- The additional weight will make your vehicle noticeably slower when stopping and starting
- As a result of needing more acceleration over time to get your heavier vehicle up to speed, you’ll use more fuel. So, overloading your car will cost you more money on refuels over time
If you have low tyre pressure, your handling will be adversely affected.
How should a load be carried on a roof rack?
Roof racks and boxes are a great way of carrying large or awkward items, but you’ll need to stay within the maximum permitted roof load.
- The limit may be lower than you think so check your handbook
- Ideally, weigh everything you're going to carry
- Remember to include the weight of the roof rack itself
- It's generally better to carry bulky but light things on the roof and heavy items inside the car
- Don't forget the extra height. Many covered car parks will be out-of-bounds with a roof box on the car
Anything carried on the roof must be attached securely:
- The Highway Code simply says: "you must secure your load and it must not stick out dangerously"
- The airflow will try to lift the front of any long load so you’ll need a secure fixing holding the front of the load down
- A fixing to the rear will stop a heavy load from sliding forwards under braking
- Ropes and straps can work loose. Stop regularly to check that they're still secure
There are also some laws around roof racks:
- Any items on the roof must not obstruct the driver's vision in any way
- Items can protrude no more than 50cm from the sides or rear of the car
- Items can protrude no more than 15cm over the front of the car
- Items on the roof cannot exceed more than 100kg
Understanding vehicle weight
In very simple terms, the vehicle weight is the weight of your car plus any added cargo. It's important to understand the weight of your car to make sure you don’t exceed its limits and can drive it safely.
Here are some vehicle weight terms explained:
Unladen weight
Unladen weight is the weight of your car when it’s completely empty. It includes the body of the car and all its parts.
Maximum Authorised Mass (MAM)
As we’ve already seen, MAM is the weight of your car plus any additional weight it can safely carry on the road. It can be found on the VIN plate or sticker on your car.
Downplating
Also known as ‘downrating’, downplating is when you reduce the maximum legal weight your vehicle can carry.
This usually happens for one of two reasons. Firstly, there are certain license restrictions that apply to drivers who are 70 years old or don't have the C1 category on their license.
Secondly, some owners opt for downgrading to decrease Low Emission zone payments, as reducing payload allowance puts them in a cheaper category.
Once a vehicle has been downplated, a revised lower weight sticker will be shown on the plate.
Conclusion
If you put too much weight in your car, several problems can occur.
For one, you’ll suffer from reduced handling and performance, with stopping, starting and turning all negatively affected. You may also see an increase in the amount of wear and tear on key components within your car, such as the engine, suspension, brakes and tyres – leading to costly repairs.
However, if you stick to the guidance in this article and always be mindful of your vehicle's weight, you'll significantly reduce the risk of vehicle issues occurring in the future.