Signs You Are Overloading Your 4x4

Before you load up your 4×4 or connect a heavy trailer, you should consider your vehicle weights.

Overloading is a common issue for Australian 4×4 owners as tradies, off-road drivers and road-trippers carry more and more weight with their vehicles. It’s important to know the weight limits of your vehicle in order to stay safe, legal and within the requirements of your insurance policy.

If you’re unsure of your vehicle weights, or you think you might be overloading your 4×4, contact your nearest Pedders store and get peace of mind today – don’t risk it!

What are all of the different terms when it comes to load-carrying?

GVM – Gross Vehicle Mass

Gross Vehicle Mass (GVM) refers to the total weight of the vehicle and includes fuel, passengers, cargo, vehicle accessories and anything else that adds weight such as a trailer. Every vehicle has a GVM rating which is the maximum weight limit of the vehicle. Exceeding GVM is dangerous, illegal and could void your insurance policy in the case of an accident. A second stage manufacturer like Pedders can legally increase your GVM by upgrading your vehicle’s suspension and brakes.

GCM – Gross Combined Mass

Gross Combined Mass (GCM) refers to the total weight of the vehicle plus the weight of a towed trailer. Most vehicles have a maximum GCM, or if a GCM is not quoted it can be calculated by summing the GVM and maximum Towing Capacity.

Tare Mass

Tare Mass is the original vehicle weight from the manufacturer – it includes all of the necessary fluids, such as oil and coolant, at their maximum levels, plus ten litres of fuel. Tare Weight does not include the weight of any passengers or cargo.


Payload is the difference between Tare Mass and Gross Vehicle Mass (GVM). It is the total amount of weight that can be legally carried by the vehicle while remaining within the maximum GVM limit.


Aggregate Trailer Mass (ATM) is the total weight of the trailer when it is not connected to a tow vehicle. ATM is the weight to consider when considering maximum vehicle Towing Capacity.

Gross Trailer Mass (GTM) is the total weight of a trailer once it is connected to the tow vehicle. Typically trailers exert approximately 10% of their total weight onto the vehicle as Towball Down Weight. GTM is equal to the Aggregate Trailer Mass minus the Towball Down Weight.

Towing Capacity

Towing Capacity is the maximum trailer weight that the vehicle is legally able to tow. Usually Towing Capacity is broken down into braked weight and unbraked weight – and most vehicles are able to tow more when the trailer is fitted with a braking system. Aggregate Trailer Mass (ATM) is used when considering Towing Capacity.

How do I know I’ve overloaded my 4×4?


Your vehicle sags significantly in the rear when towing or carrying heavy loads

If your vehicle sits very low in the rear and high in the front, it may be overloaded. You may also feel your suspension bottom out as your springs struggle to manage the weight – this feels like an abrupt stop in your suspension’s travel and may make a loud thud as the bump stop quickly reaches its maximum compression.


Your vehicle suffers from bad wheel alignment and irregular tyre wear

When your vehicle sags in the rear it generally increases the height of the front suspension and causes wheel alignment issues. You may find your tyres wear un-evenly because of this – your front tyres in particular will show more wear on the outer edges than normal.


As a result of the weight, your vehicle handles poorly particularly in wet conditions

Another common issue with sagging rear suspension is light or vague steering. This is caused by the front suspension becoming unloaded which reduces handling and braking performance, especially in wet conditions where you are more likely to experience aquaplaning.


Your vehicle struggles to stop and suffers from brake fade during normal driving

When your vehicle is overloaded, its braking system is under extreme pressure. This can cause overheating of the brakes during repeated stops which results in extended stopping distances or complete brake failure. If overheating occurs you will feel your brake pedal become softer than usual – this will get progressively worse until the brakes fail completely.


Your vehicle’s mechanical components are wearing out more quickly or failing

Overloading your vehicle puts extra strain on your mechanical components such as brakes, suspension and driveline. If you’re experiencing parts failure or excessive component wear it may be due to the weight you are carrying.



The best way to definitively know if your vehicle is overloaded is to have it weighed at a weigh bridge, or weigh service, against its maximum GVM and Towing Capacity weights.



How do I prevent my 4×4 from being overloaded?


Weigh your vehicle

You can weigh your vehicle along with any accessories, cargo or trailers at a local weighbridge or at your nearest Pedders store. By weighing your vehicle – and trailer if you tow one-, you can accurately determine if you are within your vehicle’s weight limits. If you find you are overloaded, don’t stress – contact Pedders and our team will provide a load-carrying solution that’s suited to your needs.


Book a Pedders Tow & Load Assessment

Pedders are the towing and load-carrying experts and we pride ourselves on offering advice to keep motorists safe and legal while on the road. The Pedders $75 Tow & Load Assessment is designed to help customers accurately determine the weight of their vehicle, calculate available payload and adjust or reposition cargo to ensure weight is balanced for maximum safety. Our team will also inspect your vehicle and recommend any towing and load-carrying parts if they are required or will improve your vehicle’s safety.


Get a GVM+ Upgrade for your vehicle

It is possible to increase the maximum GVM rating of a range of popular 4×4 vehicles via a second-stage manufacturer license and engineering program. After a GVM+ Upgrade, your vehicle will be able to carry significantly more weight safely and legally with an increased Payload capacity of up to 900kg for some models. Pedders offers GVM+ Upgrades that are legal Australia-wide and designed to suit most popular 4×4 and Ute models. Pedders GVM+ Upgrades are fit for purposed and engineered for heavy loads!



Concerned about your vehicle weights? Get in touch with your nearest Pedders store today and get peace of mind!


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