You've fitted a lift and a set of chunkier tyres to your 4WD, or you're about to, and now you're wondering what happens if you get pulled over on the Hume. Will it pass a roadworthy? Will your insurer still pay out? It's a fair worry, because the rules for what's legal in Victoria are stricter than a lot of forum threads make out.
Here's the short version. In Victoria, an off-road 4WD can run a total lift of up to 75mm without an engineering certificate, but only if it's done the right way: up to 50mm from the suspension, plus up to 25mm from bigger tyres, using a tested kit made for your vehicle. A 3 inch lift from the suspension alone, or anything past 75mm total, crosses the line and has to be certified. Getting that split wrong is what gets a 4WD defected, and what can leave you uninsured when it matters most.
Quick guide: what's legal without certification (off-road 4WD)
| Modification | Allowed without a certificate | Needs a VASS certificate |
|---|---|---|
| Suspension lift | Up to 50mm | More than 50mm |
| Bigger tyres (diameter) | Up to 50mm over the placard size | More than 50mm over |
| Total height (suspension + tyres) | Up to 75mm, using a tested 4WD kit | More than 75mm |
| Wheel track (how far wheels stick out) | Up to 25mm wider | More than that |
| Wheel spacers | Only if fitted by the maker | Not allowed otherwise |
The 75mm allowance is a 50mm suspension lift plus a 25mm lift from tyres (a 50mm bigger tyre diameter). It applies to off-road 4WDs fitted with a commercially made, tested kit.
The 50mm rule, in plain terms
Victoria lets you raise most vehicles by up to 50mm without paperwork. This is called an 'owner certified' modification, which means you don't need an engineer to sign it off, as long as the work follows the rules.
That 50mm isn't just the suspension. It's the total height you add, measured from factory. So if your springs lift the car 40mm and your bigger tyres add another 25mm, that's 65mm all up, and you've gone past the basic limit. The suspension and the tyres both count.
One more catch: your 4WD has to keep enough suspension travel. Travel is how far the wheels move up and down. The common benchmark is keeping at least two-thirds of the original travel. Lift it too far with the wrong parts and you lose that, which hurts the ride and the handling.
Is a 3 inch lift legal in Victoria?
Yes, but with a clear condition. A 3 inch lift is about 75mm, and Victoria has a special allowance for off-road 4WDs that lets you reach 75mm of total height without an engineering certificate. The catch is how you get there.
The legal 75mm is made up of two parts:
- Up to 50mm from a suspension lift
- Up to 25mm from bigger tyres (a tyre that's 50mm larger in diameter)
So a 50mm suspension kit plus a sensible jump in tyre size can be legal and certificate-free. A 3 inch lift from the suspension alone is a different story. That's 75mm from springs only, which blows past the 50mm suspension limit and has to be certified.
There's a second condition that trips people up. The kit has to be a commercially made one, designed and tested for your exact make and model, and fitted to the maker's instructions. Keep the paperwork that comes with it. This matters because most modern 4WDs have ESC (electronic stability control, the system that helps stop a skid), and a cheap kit off the internet can throw it out. A tested kit is one that's been checked not to.
When you need a VASS engineering certificate
Go past the owner-certified limits and you'll need a VASS approval certificate. VASS stands for Vehicle Assessment Signatory Scheme. In plain terms, it's a qualified engineer (a 'signatory') inspecting your 4WD and signing off that the changes are safe and legal.
Once they approve it, they fit a blue modification plate and issue the certificate. For a light vehicle that certificate is valid for 30 days, so you then need to take it to VicRoads for an inspection inside that window.
Cost is harder to pin down, because VicRoads doesn't set the price. The signatory quotes you based on the work involved. As a rough guide, budget a few hundred dollars for a straightforward certificate, plus the separate VicRoads inspection fee. Bigger lifts can cost a fair bit more, because they may need a handling test on a track, and some signatories won't certify large suspension lifts at all.
Costs are a guide only. VicRoads doesn't set VASS fees, so a signatory quotes each job individually. Confirm current pricing before you commit.
Skipping certification is a false saving. An uncertified lift can earn you a defect notice (the 'canary' sticker that pulls the car off the road until it's fixed). It can also void your insurance. If your modifications aren't legal, or you haven't told your insurer about them, they can refuse to pay a claim, even if the crash had nothing to do with the lift. Check your policy and tell your insurer what you've fitted.
How big can your tyres go?
On an off-road 4WD, you can fit tyres up to 50mm larger in diameter than the size on your tyre placard (the sticker in the door frame or fuel flap) without a certificate. Two conditions: the tyres can't stick out past your guards when the wheels are straight, and they can't rub on the body, brakes, suspension or steering at full lock or over bumps.
This is where 35 inch tyres come unstuck. On most dual-cab utes and wagons the factory tyre is around 31 to 32 inches, so jumping to 35s is well over the 50mm limit. That makes 35 inch tyres a certified modification in Victoria on most 4WDs, not an owner-certified one.
Bigger tyres also change two things you can't see. Your speedo reads slow, because the wheel travels further with each turn than the factory set-up expects. A 50mm bigger diameter is roughly a 6% increase, so when your speedo shows 100, you're really doing closer to 106. Braking distances also stretch a little, because there's more weight out at the wheels. Neither is a deal-breaker, but both are worth knowing before you size up.
Mild and legal, or a big build with paperwork
The right setup depends on how you drive.
If your 4WD is a daily driver that does the Hume Freeway run and heads up to the High Country on weekends, a 50mm suspension kit with a modest tyre upgrade is the sweet spot. It clears rougher gravel tracks, tows better, stays legal and certificate-free, keeps your insurance simple, and barely touches your speedo. For most touring 4WDs around Wallan, that's the smart build.
If you're building a dedicated tracks rig with 35s and four inches or more of lift, you're into certified territory. That means a VASS certificate, the extra cost, and the chance the test or the signatory says no. It can be done, but go in knowing it's a bigger job with more paperwork, not a weekend bolt-on.
Not sure which side of the line your plans sit on? Before you spend on parts, book a suspension and lift assessment at Service Plus in Wallan. We'll work out a setup that suits how you drive, the Hume commute, the gravel, and the High Country trips, and make sure it stays legal and insured. Get it sorted before you're explaining it to someone on the side of the road.
Frequently asked questions
Yes, as long as it's within the owner-certified limits or certified, the tyres don't foul or stick out past the guards, and the suspension parts are in good condition. A lift that's over the limit and uncertified can fail.
Yes. The 75mm is the total height added from factory, so a body lift, a suspension lift and bigger tyres all count together.
You can, if it wasn't done with a tested kit made for your vehicle, if the tyres rub or stick out, or if you've lost too much suspension travel. The height limit is only part of the rule.
They can. If the tyres or lift aren't legal, or you didn't tell your insurer, a claim can be refused. A quick call to list the mods is worth the few minutes.
