A GVM (Gross Vehicle Mass) upgrade is a certified suspension and load-carrying system modification designed to increase your vehicle's legal weight limit. It allows you to safely and compliantly carry more load by upgrading the suspension to heavy-duty components such as coil or leaf springs, shock absorbers, and sometimes ancillary components like brake lines or sway bars.

From the factory, many 4WDs and commercial vehicles have limited payload capacities that can be easily exceeded with the addition of common accessories like steel bullbars, roof racks, winches, canopies, or long-range fuel tanks. A GVM upgrade ensures you're operating within the law while also maintaining optimal ride quality and handling.

If you wish the explore the topic more, we wrote these blog posts articles where we explained it more in depth:

GVM / BTC Upgrades – what are they and why are they important?

Understanding Vehicle Weights

The cost of a GVM upgrade in Australia typically ranges from $2,500 to $6,000, depending on the vehicle make and model, whether the upgrade is done pre- or post-registration, and the components used.

Pricing can also vary based on brand (e.g., Lovells, Terrain Tamer, or Tough Dog), and whether additional certifications or engineering reports are required in your state.

For the most accurate quote, contact us with your vehicle details and whether you're upgrading before or after first registration.

Yes, GVM upgrades are legal in Australia, provided they're carried out by authorised installers and certified to meet your state or territory’s regulations.

Each jurisdiction (NSW, QLD, VIC, etc.) has its own requirements regarding engineering approval, certification plates, and compliance documentation.

All Four x 4 Spares is an authorised GVM upgrade fitter and can guide you through the compliance process, whether your vehicle is new or already registered.

A typical GVM upgrade includes:

Heavy-duty front and rear suspension components (springs, shock absorbers)

Compliance documentation and load rating plates

Engineering certification (if required for post-rego upgrades)

Inspection and testing to meet ADR and state transport requirements

Some kits may also include sway bar upgrades, bushes, or driveline components depending on the new GVM target and application.

If you frequently carry heavy loads, tow trailers, or have added weighty aftermarket accessories to your vehicle, a GVM upgrade is not just worth it, it’s essential. Operating over your factory GVM is unsafe, illegal, and can void your insurance.

Upgrading your GVM ensures:

• You're operating within legal limits

• Insurance and liability compliance

• Safer braking, handling, and overall control

• Reduced wear on suspension and driveline

No. A GVM upgrade doesn’t automatically reduce your towing capacity, but it doesn’t increase it either. The Braked Towing Capacity (BTC) and Gross Combination Mass (GCM) remain as set by the manufacturer unless you undertake an approved GCM upgrade (if available).

What it does do is increase how much weight your vehicle can carry, which is especially helpful for setups like touring rigs, tradie utes, and tow vehicles.

Some manufacturer-approved GVM upgrades also come with an approved GCM increase, particularly pre-registration. For example, Lovells offers GCM upgrades on select vehicles where applicable.

Post-registration, GCM upgrades are not always legally recognised, depending on your state. We can help determine your eligibility and available options based on your vehicle and location.

A GVM upgrade involves:

1. Assessing your current suspension and load capacity

2. Installing heavy-duty components rated to support the upgraded GVM

3. Conducting compliance inspections

4. Supplying and fitting certification plates

5. Lodging documentation with state transport authorities

Yes, this is known as a post-registration (post-rego) GVM upgrade. It’s slightly more involved than a pre-rego upgrade because it requires engineering approval and inspection, but it's completely legal when done through an authorised fitter.

We’re qualified to carry out post-rego GVM upgrades and manage the certification process on your behalf.

You likely need a GVM upgrade if:

• You've fitted accessories that add weight (e.g. drawers, bullbars, dual batteries)

• You tow regularly or carry heavy gear

• You're exceeding your payload capacity and risking legal penalties

• You want to remain insured and compliant while improving ride quality under load

Only authorised and accredited GVM upgrade installers can legally supply and certify a GVM increase. At All Four x 4 Spares, we're approved to fit GVM kits from major brands such as Lovells, Tough Dog, Terrain Tamer or Outbackk Armour, and we handle the paperwork, inspection, and compliance steps for you.

If your vehicle is already registered, yes post-registration upgrades require an engineering certificate (e.g., from a VSCCS engineer in NSW). For brand new vehicles, upgrades can be completed pre-rego without engineering, provided it’s done before first registration.

Exceeding your vehicle’s GVM can lead to:

Fines and defect notices

Insurance voidance in the event of an accident

Compromised braking and suspension performance

Accelerated wear on mechanical components

Unsafe driving conditions

Yes but only if the upgrade is completed by an approved workshop and accompanied by appropriate engineering certification. Each state in Australia has different processes, and we’re across all of them to help you stay compliant.

• Vehicle inspection and consultation

• Quote and recommended GVM kit

• Installation of suspension upgrade

• Certification and paperwork preparation

• Registration update with RMS or relevant authority

Yes in a good way. A compliant GVM upgrade ensures your vehicle remains insurable and legally registered, provided it’s certified and documented correctly. It can actually help you avoid future insurance complications related to overloading.

Yes, but not all lift kits are compatible with GVM upgrades. Approved GVM kits are usually tested to ADR standards as a complete package. We’ll advise on compatible lift heights and whether accessories can be installed before or after the upgrade.

Yes. Pre-rego upgrades are completed before first registration and do not require engineering approval making them easier and more cost-effective. Post-rego upgrades require certification by a licensed engineer and approval by your local transport authority.