Introduction
A road trip is always a great idea!
However, if you are travelling with heavy luggage and placing it on your roof, you must determine how much weight your car can hold.
This is especially true for smaller cars. Every vehicle has a safe weight limit and this safe weight limit is quite easy to find too.
Going beyond your car’s maximum load capacity can have serious consequences for your car's passengers and the other families on the road.
In this article we will help you with the following:
Where do I find my Weight Limits?
How much weight can your car carry?
You can find your car’s weight limit in two main places:
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the user manual
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and the sticker on the door of the driver’s seat.
Some car manufacturers place this weight limit plate or sticker on the back of the car too.
Vin number & weight limit sticker by SpotDem
The owner’s manual provides a detailed account of the gross vehicle mass, the roof load, and the gross combined weight. If you do not have your car’s manual, you can easily find it on the brand’s website or download it as a document on your device.
For instance, you can consult and download the owner’s manual of the Mercedes Benz C-class 2021 from the website.
Links to other popular car brands manuals:
What happens if the Load Exceeds the Vehicle's Weight Limit?
Vehicles react differently when loaded with weights exceeding their load limits. It also depends on the nature of the load and whether it is evenly distributed on the axles. But invariably, in all overloaded vehicles, you will feel instability while driving. You may feel okay with it, but in fact, it poses a safety risk.
Here is what you should expect when you overload your vehicle:
1. Overloading your car will make it harder to steer and take longer to stop as it adds extra strain to your brakes. In extreme situations, on the road you may be at risk of your brakes failing which can pose a fatal risk.
2. The loaded weight puts a heavy strain on the tires, which can overheat and wear them rapidly. In addition to the tire damage and maintenance costs, excessive strain on the suspension and tires increases the risk of sudden, dangerous failures such as blowouts.
3. Additionally, if you are involved in an accident or a crash, and there is evidence that your vehicle was overloaded the insurance company may be within their right to reject your claim.
4. If you get caught driving an overloaded vehicle, the law enforcement officer can charge you a penalty, issue you a driving notice, or even a court summons.
What is the law in the UK if you overload your vehicle?
The Driver and Vehicle Standards Agency (DVSA) has a set of regulations and penalties that ensure road safety and the protection of public roads and sidewalks. This department conducts inspections and imposes fines and penalties for commercial vehicles.
For passenger cars and SUVs, the traffic police will be the ones to point out. Driving an overloaded vehicle is a punishable offence under the law, with a penalty of up to 300 British pounds. You can get an overloading ticket, they can prohibit you from taking your journey further, and you may have to pay a heavy penalty to get your car back.
The police or the law enforcement officer can give you a ‘direction to drive’ notice with clear instructions for stopping and unloading your vehicle at a certain place or police station on the way.
If your car is seen losing control or stability due to the load, the officer can also issue a court summons in addition to the offence of vehicle overload.
Understanding your Car’s Weight Limits
Some cars offer enough space for all your baggage. But when passenger space is more important, you will have to consider the roof for all the travel gear.
For loading the gear without compromising road safety and risking vehicle damage, it is important to understand the weight limits of your car.
If you are using a car roof for camping, you need to know the static weight limit of your vehicle. But if you are travelling with luggage and weight on the roof, a dynamic weight limit instead will apply.
Static Weight Limit
Static weight limit is the load weight a car can safely hold when it is stationary.
The static weight rating is much higher than the dynamic weight limit.
Other frequently used terms for Static Weight Limit:
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Gross Vehicle Weight Restriction
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Gross Vehicle Weight Limit
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Total Permissible Vehicle Weight
Dynamic Roof Weight Limit
Dynamic weight limit is the weight the roof of a vehicle can safely carry while moving.
When calculating the weight of the belongings to go on the roof, don’t forget to include the weight of the cross bars and racks.
Other frequently used terms for Dynamic Roof Weight Limit:
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Roof Load
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Dynamic Roof Capacity
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Permissible Roof Load
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Dynamic roof weight rating
Roof Rack and Rooftop Tent Weight Limits
When looking at how much weight can a car hold, it is important to note the weight ratings of the roof rack and the rooftop tents.
At first this can be tricky to understand but once you get it, you get it.
These are the main pieces of information you'll need:
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The Dynamic Roof Weight Limit of your car
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The Dynamic Weight Limit of your roof bars or roof rack
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The weight of your roof bars or roof racks
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The weight of your Roof Tent
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The weight of any additional car roof items
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The Static Weight Limit of the car
Using the above we are going check the following weight calculations:
For your roof bars make sure the:
Rooftop Tent Weight + Additional car roof items
is less than
Dynamic Weight Limit of the Roof Rack
For your car roof load make sure the:
Rooftop Tent Weight + Roof Rack Weight + Additional car roof items
is less than
Dynamic Roof Weight Limit
For your Static Weight Limit make sure the:
Gross vehicle weight + Roof Tent + Roof Rack + Additional car roof items + Luggage + Passengers
is less than
If you're still a bit confused and you wish to go through a step by step example then continue reading below:
Let's get calculating!
We'll get calculating step by step with examples.
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What's the Dynamic Roof Weight Limit of your car
After you've lookup it up in the car manual then we know the weight limit budget we are working towards.
Example:
That means we've got 70kg to play with for the entirety of the items on the roof.
If you're looking to carry items on your roof you will need to plan in advance the items you will be carrying.
This could be your luggage, sports equipment or a rooftop tent to sleep in.
And you'll definitely need roof bars or roof racks to hold these in place.
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The Dynamic Weight Limit of your roof bars or roof rack
When purchasing your roof bars it's important to understand the dynamic weight limit of the roof bars itself.
This is because the total weight of what you wish to carry must be within this limit.
Example:
This means that your weight budget is 60kg to carry items on the roof bars. So if you're thinking about purchasing a rooftop tent then the weight of the roof tent must be below 60kg.
Let's say you choose the Latitude Pioneer Green as your rooftop tent which is 54kg
This satisfies the following calculation:
For your roof rack or roof bars:
Additional car roof items can be anything from additional luggage in a storage box or a car awning which are typically attached to your roof bars or roof rack system.
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The weight of your roof bars or roof racks
Now let's quickly check the weight of the roof bars you've chosen.
Example:
The weight of the roof bars are 8kg
Excellent news. We know that the weight of our rooftop tent is 54kg and the weight of the roof racks are 8kg.
This satisfies the following calculation:
For your dynamic roof weight limit of your car:
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The Static Weight Limit of your car
We're almost there!
Finally, we need to know the Static Weight Limit of your car which could be phrased as Gross Vehicle Weight Restriction or Gross Vehicle Weight Limit.
Remember, this is the total weight limit of the empty car plus any additional load.
Therefore, we need to know a rough estimate of the weight of your luggage, passenger weight and any additional roof items to add to the rooftop tent and roof rack.
Example:
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The Static Weight Limit is 3,000kg
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The weight your luggage is 20kg
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The weight of a passenger is 70kg and there are four passengers
Perfect!
This satisfies the following calculation:
Gross vehicle weight + Roof Tent + Roof Rack + Additional car roof items + Luggage + Passengers < Static Weight Limit the Car
Gross vehicle weight (2,000kg)
+ Roof Tent (54kg)
+ Roof Rack (8kg)
+ Additional car roof items (0kg)
+ Luggage (20kg)
+ Carrying Four Passengers (4 x 70kg = 280kg)
= 2,362 kg
< Static Weight Limit the Car (3,000kg)
We're all set! Now you can get going picking out your roof bars and rooftop tents understanding the weight limits of your car.
If you add all the items up on the left side of the calculations then you've exceeded the maximum load or carrying capacity of your vehicle where we highly recommend you to reduce the amount of weight you carry.
One final tip:
It is important to increase the tire pressure on all four wheels when carrying a heavy load. This information should be found in the car owners manual. You adjust the air tyre pressure at most petrol stations across the UK.
Once you're not carrying a heavy load remember to reduce your tyre pressure back to the normal recommended level.
How to Calculate Towing Capacity
The towing capacity of your vehicle is the maximum weight it can tow when pulling a trailer. Most cars will provide this information in the car manuals or via weight limit stickers.
If you cannot find your vehicle’s towing capacity anywhere in the manual, here is a simple way to calculate it.
There is an 85% rule that most people like to use. This rule suggests that the fully laden mass of the caravan or the trailer should not exceed 85% of the kerb weight of the towing vehicle. A vehicle's towing capacity depends on many factors, and the 85% rule only gives you a safe estimate of the towing capacity.
Some vehicles are designed for towing masses equal to the listed vehicle weight as well. Here is a more authentic way to calculate it:
1. Look at your vehicle's gross combined mass (GCM) in the owner’s manual.
2. Subtract the gross vehicle mass (GVM). Also, deduct the weight of any accessories, passengers, or luggage your vehicle carries.
3. This gives you the gross trailer mass (GTM) for your vehicle.
The weight of the trailer and the vehicle combined with anything else that it is carrying should be less than the gross combined mass listed by the manufacturer.
