Wheels: offset, PCD and what actually bolts on
A wheel that bolts on is not the same as a wheel that fits. Four separate numbers have to agree, and only one of them is obvious from looking at it.
Tyres are a different problem with different numbers — the tyres guide covers load rating, LT versus P, and what upsizing costs you. This is about the rim.
PCD: the stud pattern
Written as a count and a diameter — 6x139.7 means six studs on a circle 139.7mm across.
The trap is that patterns close in diameter look identical by eye and will start to thread up before they bind. 6x139.7 and 6x135 are both six-stud, both common on Australian utes, and both will feel wrong only after you've mounted the wheel.
Measure or look it up for your own vehicle. Don't infer it from another vehicle that "takes the same wheels".
Centre bore: what actually carries the weight
The hole in the middle of the wheel sits on a lip on the hub. On a hub-centric fitment, that lip carries the vehicle's weight and the studs only clamp the wheel to the hub. That is how nearly every factory wheel is designed.
Aftermarket wheels are often made with a larger bore so one wheel suits several vehicles, and are brought back to size with spigot rings. Fitted correctly that is fine. Left out, the studs end up carrying weight they weren't designed to carry, and the usual symptom is a vibration nobody can balance out.
If a wheel needs spigot rings, they are part of the purchase, not an optional extra.
Offset: the number that changes the vehicle
Offset — often written ET — is the distance from the wheel's mounting face to its centreline. Lower or negative offset pushes the wheel outward; higher offset tucks it in.
Pushing the wheels out is the usual reason people change offset, and it changes more than the look:
- Track width increases, which is regulated. Australian rules limit how much wider the track may get before the vehicle needs certifying, and the allowance is smaller than most people assume. Check VSB14 and your state's requirements before ordering, not after.
- Scrub radius changes, which alters steering feel and how the vehicle behaves under brakes, particularly on a surface that's slippery under one side.
- Wheel bearings carry more leverage. A wheel further out is a longer lever on the same bearing. This is a wear problem rather than an immediate one, which is why it's easy to dismiss.
- Guard clearance at full lock and full suspension compression is what actually decides whether it rubs. A wheel that clears in the driveway can foul on a stuffed suspension travel it never sees until it's loaded.
None of that makes changing offset wrong. It makes it a decision rather than a styling choice.
Rim load rating
Every rim has a maximum load in kilograms, and it is per wheel. It's easy to overlook because tyres get all the attention on this — but a rim rated below what the corner of your vehicle weighs is a problem regardless of what tyre is on it.
It matters most on the vehicles this site is about: a loaded touring ute is heavy, and it gets heavier after a GVM upgrade. If you have raised GVM, re-check the rims against the new mass, not the old one.
Work out what your vehicle actually weighs with the payload calculator before you assume.
Steel or alloy
Neither is the answer.
Steel bends rather than cracks, which means a hit that would write off an alloy can often be hammered back well enough to get home. It's cheaper, heavier, and easier to repair in places where repair is the only option.
Alloy is lighter — which is unsprung weight, so it genuinely helps ride and steering — dissipates heat better, and is available in far more offsets and finishes. A hard enough impact cracks it, and a cracked alloy is finished.
Remote touring tends to favour steel for the repairability. Most other use favours alloy.
Beadlocks are mostly not road legal here
True beadlock wheels clamp the tyre bead with an outer ring. They're excellent at very low pressures and generally not approved for road use in Australia. "Beadlock-style" wheels have the look and none of the function — which is fine, as long as you know that's what you're buying.
What to give the retailer
Your vehicle and series, the PCD, the centre bore and whether spigot rings are included, the offset you're moving from and to, and the rim load rating. If you've had a GVM upgrade, say so — it changes which rating you need.
And ask what the track increase works out to, in millimetres, before you order.
This guide is general information, not fitting or engineering advice. Fitment, compliance and safety depend on your specific vehicle — confirm with the retailer and a qualified fitter before you buy.