Tyres rarely wear evenly, and that's actually useful. The way rubber comes off a tyre records how the car has been set up and driven. Learn to read it and you'll catch pressure, alignment and suspension problems early, long before they cost you a set of tyres.
You don't need any tools. Next time the car is parked on level ground with the steering straight, crouch beside each tyre, run your hand across the tread (carefully, as exposed steel on a badly worn tyre can be sharp) and compare the inside edge, the centre and the outside edge. Here's what the common patterns mean.
Worn in the centre
If the middle of the tread is noticeably lower than both edges, the tyre has been running over-inflated. Too much pressure makes the tyre bulge slightly, so the centre carries most of the load and wears first. Check the placard on the driver's door jamb for the recommended pressure and set the tyres when cold. Adding "a few extra psi" for economy is a common habit that quietly shortens tyre life.
Worn on both edges
The opposite pattern, with both shoulders worn and the centre still healthy, usually means under-inflation. A soft tyre sags, lifting the middle of the tread and putting the load on the edges. Under-inflated tyres also run hotter and use more fuel, so it's worth fixing promptly. If the pressures were right but the edges are still going, the car may regularly be carrying heavy loads or towing without the pressures being adjusted to suit.
Worn on one edge only
Wear on just the inside or outside shoulder points to a wheel alignment problem, most often camber, which is the tilt of the wheel when viewed from the front. Inside-edge wear is especially easy to miss, because you can't see it without turning the steering or getting low beside the tyre. It's frequently the result of a hard knock against a kerb or pothole, worn suspension bushes, or a car that has been lowered. An alignment check will confirm it, and if a component is worn, fixing that first stops the problem coming back.
Feathering (saw-tooth edges)
Run your palm across the tread blocks in both directions. If it feels smooth one way and rough or jagged the other, the tread blocks are being scrubbed sideways as the tyre rolls. This is toe misalignment, where the wheels are pointing slightly inwards or outwards rather than straight ahead. Feathering often comes with a faint hum that changes with speed. Toe is one of the quickest alignment fixes there is.
Cupping or scalloping
Patches of tread worn lower in a repeating scooped pattern around the tyre, often with a rhythmic thump or drone when driving, usually mean the tyre is bouncing rather than rolling smoothly. Common causes are worn shock absorbers or struts, a wheel that's out of balance, or a bent rim. Replacing the tyre without addressing the cause means the new one will cup too.
Flat spots
A single bald patch on an otherwise even tyre is nearly always the result of a heavy skid, such as a locked wheel on gravel or an emergency stop in an older car without ABS. Tyres can also flat-spot if the car sits for months without moving. Check the depth in the flat area against the 1.5 mm legal minimum: if it's close, the tyre needs replacing, and if the patch is deep enough to feel as a thump, don't wait.
Front tyres wearing faster than rears
On most front-wheel-drive cars this is normal. The front tyres steer, brake hardest and put the power down, so they can wear twice as fast as the rears. Regular rotation, roughly every 10,000 kilometres or at each service, evens this out and gets the most from the set. What isn't normal is one front tyre wearing much faster than the other, which usually points back to alignment or a dragging brake.
What to do about it
- Fix the cause first. New tyres on a misaligned car will wear the same way.
- Check pressures monthly when the tyres are cold, and adjust for heavy loads or towing.
- Rotate regularly so wear is shared across the set.
- Get an alignment after a big impact, after suspension work, or whenever the steering wheel sits off-centre.
- Don't ignore noise. A new hum, drone or vibration is often the first sign of a wear problem developing.
A quick look at your tyres every few weeks is one of the cheapest maintenance habits there is, and it pays for itself in longer tyre life and safer handling. If you've spotted a pattern you're not sure about, or the steering just doesn't feel right, the team at Global Tyres Geelong in North Geelong VIC can check your wear, pressures and alignment and tell you plainly what, if anything, needs doing.