How to Read Tyre Wear Patterns Like a Mechanic

Mechanics can glance at a tyre and tell you what is wrong with a car’s pressures, alignment or suspension — not because it is magic, but because tyres wear in predictable ways. This is the hub guide to every common pattern, what each one means, and where to go next. Keep it handy the next time you crouch down beside your car with a torch.

Contents

• How to inspect your tyres properly
• Both shoulders worn: underinflation
• Centre worn: overinflation
• One edge worn: camber and toe
• Sawtooth feel: feathering
• Scooped dips: cupping and scalloping
• Flat spots and single-tyre wear
• The quick-reference wear chart

How do you inspect your tyres properly?

Do it with the car cold and parked on level ground. Look across the full width of each tyre, from inner shoulder to outer shoulder, and run your hand across the tread in both directions to feel for a sawtooth edge you cannot see. Check all four, because the pattern often differs front to rear. Note anything uneven: a low centre, a low edge, scooped dips, or one tyre clearly worse than its neighbours. The Australian legal minimum is 1.5 mm of tread in all principal grooves, and the built-in wear indicators sit at that height.

What does wear on both shoulders mean?

If both outer edges of the tread are worn while the centre still has depth, the tyre has been running underinflated. Low pressure lets the tyre sag so the shoulders carry the load and the centre lifts off the road. This is the dangerous one: underinflation builds heat, hurts fuel economy and, at its worst, leads to blowouts. The cure is to set pressures to the placard and check them regularly. Read more on what happens if you underinflate your tyres.

What does centre wear mean?

Wear concentrated in the middle of the tread with healthy edges is the signature of overinflation. Too much pressure crowns the tyre so only the centre contacts the road, wearing it faster and reducing grip and braking. The fix is again the placard pressure — not the sidewall maximum, which is a limit, not a target. See centre wear explained, what happens if you overinflate, and why you follow the placard, not the sidewall maximum.

What does wear on just one edge mean?

When only the inside edge or only the outside edge is worn while the rest of the tread is even, the culprit is alignment — usually camber, often with toe involved. Excessive negative camber wears the inner shoulder; excessive positive camber wears the outer shoulder. This is an alignment issue, not a pressure one, so no amount of inflation will fix it. Understanding camber, caster and toe makes the printout at the alignment shop far easier to read.

What does a sawtooth feel across the tread mean?

If the tread depth looks fine but the ribs feel sharp one way and smooth the other when you slide your hand across them, that is feathering, caused by incorrect toe dragging the tyre slightly sideways. It commonly appears on the front tyres and makes them noisier as they wear. The fix is an alignment to reset toe.

What do scooped dips around the tyre mean?

Regular scooped-out dips spaced every few centimetres around the tread — often felt as a growing vibration or growl — are cupping or scalloping. The usual causes are worn shock absorbers, struts, bushes or ball joints, or wheels that are out of balance, sometimes with misalignment on top. Because it stems from suspension or balance, the fix is mechanical, and cupped rubber cannot be restored.

What about flat spots and one tyre wearing faster?

A single flattened patch that causes a thump after the car has been parked is usually a temporary flat spot that drives out as the tyre warms; a patch ground in by a skid is permanent. If one tyre is simply wearing faster than the other three, the cause sits at that corner — a bent component, a seized brake, a balance problem or localised alignment — and our guide to why one tyre wears faster than the rest walks through it.

The quick-reference tyre wear chart

Two patterns at once are common — feathering plus one-edge wear, for example, both point to alignment. When wear is uneven, the single best first move is a wheel alignment (and how it differs from balancing), and it is worth knowing the signs your car needs one.

Frequently asked questions

How often should I check my tyres for wear?

Give them a proper look at least monthly and before any long trip. Catching an uneven pattern early can save most of a tyre’s life and a set of new ones.

Can I read wear patterns myself or do I need a mechanic?

You can spot the pattern yourself with this guide — edges, centre, sawtooth, dips. A mechanic is needed to measure and correct the underlying alignment or suspension fault.

Does uneven wear always mean alignment?

No. Both-edge and centre wear are pressure problems. One-edge and sawtooth wear are alignment. Scooped dips are suspension or balance. The pattern tells you which.

Is a worn tyre still legal if only one edge is low?

Australian law requires at least 1.5 mm across all principal grooves. If any part of the tread that must be measured is below that, the tyre is illegal — even if the rest looks fine.

This is general diagnostic guidance. Have alignment and suspension faults confirmed and corrected by a qualified fitter, and follow your vehicle’s placard pressures. Legal minimum tread depth in Australia is 1.5 mm in all principal grooves.

Sources: Yokohama Australia – Tyres 101: Wheel Alignment; Bridgestone Australia – tyre pressure guidance.