You've been told one or two of your tyres are worn out, but the others still have plenty of life left. Do you really need to replace all four? It's one of the most common questions we hear, and the honest answer is: it depends. Here's how to make the right call for your car and your budget.
When replacing two tyres is fine
If your other two tyres are in good condition — plenty of tread, no age cracking, wearing evenly — replacing just a pair is usually perfectly acceptable. Front tyres often wear faster than rears on front-wheel-drive cars, because they handle steering, most of the braking and all of the driving force. So it's normal for tyres to come due in pairs rather than all at once.
The key rule: always replace tyres in pairs across the same axle. Fitting one new tyre next to a half-worn one on the same axle creates uneven grip from side to side, which can make the car behave unpredictably when braking or cornering, especially in the wet.
When all four makes more sense
- All-wheel-drive and 4WD vehicles. Many AWD systems are sensitive to differences in tyre diameter. A new tyre has more tread — and a slightly larger rolling circumference — than a worn one, which can strain the drivetrain over time. Check your handbook; some manufacturers specify a maximum allowable tread difference across all four tyres.
- Your remaining tyres are close behind. If the "good" pair is down to 3–4 mm of tread, they may only have months left anyway. Replacing all four saves a second trip and keeps handling consistent.
- The old tyres are ageing. Tyres older than five or six years can harden and crack even with decent tread remaining. Mixing fresh rubber with aged rubber gives you uneven grip you can't see.
Where should the new tyres go?
Here's the part that surprises many drivers: new tyres should generally be fitted to the rear axle, even on a front-wheel-drive car. It feels backwards — surely the wheels doing the steering deserve the best rubber?
The reasoning comes down to how a car behaves when grip runs out. If the front tyres lose traction first, the car understeers — it runs wide, and most drivers instinctively ease off the accelerator, which helps recover. If the rear tyres let go first, the car can oversteer — the back end steps out, which is far harder for the average driver to catch, particularly on a wet road. Putting the fresher tread on the back keeps the rear planted and the car's behaviour predictable.
Can you mix tyre brands or models?
Ideally, all four tyres should be the same brand, model and size. In practice, mixing is legal in Australia as long as tyres on the same axle match in size, construction and speed rating. A different brand front-to-rear is usually fine; a mismatched pair side-by-side on one axle is not a good idea. If your original tyre model has been discontinued, a tyre shop can recommend a close equivalent in grip and handling character.
Make the remaining tyres last
Whichever way you go, a couple of habits will help your tyres wear evenly so future replacements come in neat sets of four: check your pressures monthly, rotate your tyres roughly every 10,000 km, and have your alignment checked if you notice uneven wear or the car pulling to one side.
If you're weighing up two tyres versus four, the team at Global Tyres Geelong in North Geelong can inspect your current set, measure the tread honestly and help you choose what actually makes sense — no pressure either way. Drop in or give us a call.