GVM upgrades

GVM is Gross Vehicle Mass: the most your vehicle is allowed to weigh when fully loaded. Everything on or in the vehicle counts toward it, including fuel, accessories, cargo, passengers, a tray body on a cab chassis and the tow ball load from a trailer. It is set by the manufacturer and shown on the compliance plate.

GVM is the limit for the vehicle itself. GCM is Gross Combination Mass, the limit for the vehicle and its trailer together. The tow ball load counts toward GVM, and the weight of the trailer counts toward GCM. They are separate ratings, so you need to stay within both.

Payload is how much you can add to the vehicle before it reaches its GVM. ARB describes factory payload as the GVM minus the vehicle's kerb weight. Passengers, fuel, water, accessories, luggage and tow ball load all use it up, so your real payload is often lower than the figure in the brochure.

No, not by itself. Towing capacity and GCM are separate ratings from GVM, and raising the GVM does not automatically raise either of them. Ask us what applies to your vehicle before you plan around a higher figure.

No. Upgrades are engineered for specific vehicles, and not every model or configuration has an approved upgrade. ARB's Old Man Emu kits are configured by vehicle, so the first step is to check yours. Tell us the make, model, year and variant.

It can be, when it is done through an approved process and certified correctly. ARB states that new vehicle GVM upgrades are granted by the Federal Department of Infrastructure and Transport after testing by Old Man Emu engineers, with a compliance plate fitted by an authorised installer. For vehicles that are already registered, state rules apply and they differ. This is general information, not legal advice.

Already registered vehicles fall under the state or territory authority, and requirements can differ. In Queensland, for example, the Department of Transport and Main Roads says complex modifications to light vehicles must follow an approved modification code and be certified by an Approved Person. Check your own state's rules before you commit.

It depends on the upgrade and the state. ARB refers to an authorised Old Man Emu installer and a compliance plate for new vehicle upgrades. In Queensland, TMR-accredited Approved Persons certify modifications. We supply and fit GVM upgrades, and we will talk you through the certification process for your vehicle and state before you book.

ARB states that a GVM upgrade involves fitting a complete approved suspension system, and the increase is based on that system meeting the minimum ADR safety requirements. A GVM upgrade is not a spring swap on its own.

Each axle has its own load limit, and loading the rear can change the load on the front. ARB lists front axle load upgrades of up to 170kg of verified front axle load for some popular 4x4 models, standard with a full Old Man Emu Nitrocharger or BP-51 kit. It is vehicle specific, so check yours.

ARB notes that a vehicle can become dangerous and illegal if it exceeds its GVM. An overloaded vehicle can handle and brake worse, and it may have insurance and legal consequences. Weigh your loaded vehicle to know where you stand.

It depends on the vehicle, the kit and the fitting, so we do not publish a price here. Send us your vehicle details and we can talk through your options. ARB lists some components, such as indicators, with a price on its website.