You are looking at your tyres, maybe before an MOT, maybe because a mechanic flagged it, maybe just because something looks off. One tyre is wearing in a way that does not match the others. It might be the inside edge, the centre, or patchy and irregular.
Uneven wear is one of the clearest diagnostic signals your car can give you. The pattern tells you what is wrong, not vaguely, but specifically.
We read these patterns every week. Here is what each one means and what to do about it.
Short version: uneven tyre wear is almost always caused by one of five things, incorrect pressure, wheel alignment off, worn suspension, wheel imbalance, or driving habits. The specific wear pattern tells you which.
The visual diagnostic: 7 wear patterns and what each means
Match what you see on your tyre to a pattern. The pattern gives you the cause, and the cause gives you the fix.
| Wear pattern | What it looks like | Most likely cause | Typical fix |
| Centre wear | Middle worn smooth, edges fine | Chronic overinflation | Reduce to spec, replace if below 1.6mm |
| Both edges worn | Inner and outer worn, centre fine | Chronic underinflation | Top up to spec, replace if below 1.6mm |
| Inside edge only | Inner edge much more worn | Negative camber, alignment off | Alignment £30 to £80, often a new tyre |
| Outside edge only | Outer edge much more worn | Positive camber, alignment off | Alignment £30 to £80, often a new tyre |
| Cupping or scalloping | Dips around the tread | Worn suspension | Suspension inspection, new tyre |
| Feathering | Smooth one way, sharp the other | Toe alignment off | Alignment £30 to £80 |
| Patchy or random | Irregular bald spots | Wheel imbalance or a brake lock-up | Rebalance £15 to £40, replace if from lock-up |
Match a pattern? WhatsApp a photo and your tyre size to wa.me/447955533000 and we will confirm the diagnosis before we set out.
Quick answer: what to do in the next 30 minutes
- Park on level ground and grab a torch if the light is poor.
- Look at all four tyres and compare them to each other.
- For each one, check the centre, both edges, and run your hand across the tread carefully.
- Match what you see to the table above, noting which tyre and which pattern.
- Do the 20p coin test in the main grooves to gauge tread depth.
- Photograph the worst area for reference and to send us.
- Call us with the diagnosis, and we will confirm the cause and bring matching tyres if needed.
How to check tread depth properly
The 20p coin test
Pop a 20p coin into the main tread grooves. If the outer band of the coin is visible, your tread is getting low, around 3mm, and replacement is approaching. If the band stays hidden below the tread, you have more than 3mm. Check several spots on each tyre, since wear is rarely even.
Tread wear indicators
Most tyres have small raised bumps inside the main grooves at 1.6mm. When the tread wears down level with them, you are at the legal minimum. Michelin and some others mark the spot with a small triangle or logo on the sidewall.
A tread depth gauge, the most accurate
A small gauge costs a few pounds. Press it into the main groove and read the depth. The industry recommendation is to replace at 3mm rather than wait for 1.6mm, because wet braking drops off sharply below that.
The legal position
The UK legal minimum is 1.6mm across the central three-quarters of the tread, all the way around. Below that is an MOT fail, a fine of up to £2,500 per tyre, and 3 penalty points per tyre. Visible cords or canvas is an automatic fail whatever the tread depth. You can read the full checks in the DVSA MOT rules, and Michelin’s tread guidance explains why 3mm is the safer target.
The 5 underlying causes and what to do about each
1. Incorrect tyre pressure, the most common and cheapest
Overinflation wears the centre, underinflation wears both edges. Fix: top up to the spec on your driver’s door pillar or fuel flap, and check monthly, before long trips, and when carrying loads. Our TPMS guide covers how modern cars warn you, and why older ones do not.
2. Wheel alignment off
Caused by potholes, kerbs, worn suspension, or a lowered ride height. The signs are pulling to one side, an off-centre wheel, single-edge wear, or feathering. Fix: a four-wheel alignment at £30 to £80 with a laser rig. We honestly refer this, as it is not mobile work. Our guides to pothole damage and kerbed wheels cover the usual triggers.
3. Worn suspension components
Caused by age and mileage, tired shocks, or worn ball joints and bushes. The sign is cupping or scalloping, often with clunks over bumps. Fix: specialist suspension diagnosis and replacement, typically £80 to £400 per part. We refer this to a mechanic.
4. Wheel imbalance
Caused by a lost balance weight, often after a kerb hit. The signs are patchy wear plus vibration at 50 to 70 mph. Fix: a rebalance at £15 to £40 per wheel, which we can do at the scene. Our guide to a vibrating steering wheel goes deeper.
5. Driving habits
Sharp cornering, hard braking, mounting kerbs, and hitting potholes all accelerate every cause above. Fix: gentler driving, slowing over rough surfaces, and a bit more care parking.
Front vs rear: why one axle wears faster
Front-wheel-drive cars, which is most modern UK cars, do most of the work up front, steering, accelerating, and braking. Front tyres typically wear about twice as fast as the rear, so rotating every 6,000 to 10,000 miles evens things out.
Rear-wheel-drive cars like a BMW 3 Series or Mercedes C-Class often wear the rears faster, while the fronts wear from cornering and braking. Performance cars with directional tyres have limited rotation options.
All-wheel-drive cars wear more evenly, but any mismatch can damage the differential, so many AWD makers require replacing in fours rather than pairs. Always check your handbook before buying just one or two.
Should you replace one tyre, a pair, or all four?
Replace one if:
- The other tyre on the same axle is within about 1.5mm of tread
- The other three are all in similar good condition
- It is not an AWD car
Replace a pair (same axle) if:
- The other tyre on that axle is significantly worn
- There is more than about 1.5mm tread difference between them
- You run run-flats that require axle pairs
Replace all four if:
- All four are at or near the 1.6mm limit
- It is an AWD car, per the handbook
- Several tyres show the same pattern, hinting at a systemic cause
- You have just had major suspension or alignment work
A garage that profits from alignment and suspension work might tell you the big job is the only option. We can replace the tyre and refer you to a specialist for the alignment. Different incentives lead to different advice.
Will uneven wear cause an MOT failure?
Uneven wear itself is not tested, but its consequences usually are.
Any tyre below 1.6mm in the wear zone is an automatic fail, as are exposed cords, and cuts or bulges over a certain size. A noticeably soft tyre can affect the brake test too. Beyond that, the tester will flag the wear pattern as an advisory pointing at the underlying cause, so fix that or the new tyre wears unevenly as well.
Inspect all four at least two weeks before the test. If any are close to the limit in the worn area, replace before the MOT, and sort any alignment a week ahead. That avoids retest fees and panic pricing at the centre.
Scotland-specific factors in uneven wear
Winter road salt is applied heavily from November to March, and it accelerates rubber degradation and sidewall cracking. Washing the arches and wheels through winter genuinely helps.
Spring pothole season peaks from January to March after the freeze-thaw, knocking alignment and damaging tyres, so uneven-wear callouts spike from April to June. Glasgow’s M8 at Charing Cross and the Kingston Bridge approach are common culprits.
Long M8 and M74 commutes rack up serious mileage, wearing front tyres fast on FWD cars, which makes a rotation routine more important than for low-mileage drivers.
Highland holiday returns often surface wear that was already developing, after single-track verge friction and long hill descents. Our guide to remote Scotland covers those Highland causes.
A real callout pattern we attend most weeks
We do not need to invent this one.
A Glasgow driver doing a pre-MOT check noticed the front-right tyre had a badly worn inside edge while the others looked fine. They remembered hitting a pothole on the M8 about four months earlier.
The inside-edge wear was consistent with negative camber from that impact knocking the alignment out. The tyre was around 2mm on the inside edge against 5mm on the outside, well above 1.6mm but uneven enough to draw an MOT advisory.
We confirmed it with photos, fitted a matching front tyre, and recommended a four-wheel alignment at a specialist within the week to protect the new tyre. The tyre and visit were reasonable, and the alignment went to the right people.
Need us nearby? See our pages for Glasgow, Edinburgh, Aberdeen, Dundee, and Inverness.
Tyre rotation: when, how, and why it matters
Different positions wear at different rates, and on a FWD car the fronts wear much faster than the rears. Rotating evens that out so all four reach replacement age together, which saves money over the life of the set.
The standard UK guidance is every 6,000 to 10,000 miles, ideally with a service. The basic pattern is a front-to-rear swap for non-directional tyres. Directional tyres can only swap front-to-rear on the same side, since the arrows must point in the rolling direction, and many AWD cars should not be rotated unless you are replacing all four. A standalone rotation is usually £15 to £40, and often free with new tyres or a service.
Frequently asked questions
What does uneven tyre wear mean?
It means different parts of the tread are wearing at different rates, and the pattern points to a specific cause. Centre wear is overinflation, both edges is underinflation, a single edge is alignment, cupping is suspension, feathering is toe alignment, and patchy is imbalance.
What causes tyres to wear on the inside?
Usually negative camber, where the top of the wheel leans inward and loads the inside edge. It is common after potholes, kerb hits, worn suspension, or a lowered ride height. A wheel alignment at a specialist, around £30 to £80, is the fix.
Why is the middle of my tyre worn?
Almost always chronic overinflation. The centre of the tread bulges out and carries more weight, wearing faster than the edges. Top up to the manufacturer’s pressure, not the maximum on the sidewall, and check monthly.
What is cupping tyre wear?
Cupping, or scalloping, is a series of dips around the tread, like small bowls in the rubber. It is almost always caused by worn or failing suspension, such as shocks, struts, bushes, or ball joints, and needs a specialist diagnosis.
Is uneven tyre wear an MOT failure?
The wear itself is not directly tested, but its results are. Any tyre below 1.6mm in the central three-quarters is an automatic fail, and exposed cords fail too. The pattern is flagged as an advisory pointing at the cause, so fix that or the new tyre wears unevenly as well.
Should I replace tyres in pairs?
Replace as a pair on the same axle if there is more than about 1.5mm tread difference between the two. A single is fine if the other tyre on that axle is similar. AWD cars often need fours per the handbook, so check before buying just one.
How long can I drive on unevenly worn tyres?
If all four are still above 1.6mm and no structure is exposed, you can drive, but the cause is still active and keeps eating tyre life. Address it within weeks, not months.
Will wheel alignment fix uneven wear?
Alignment fixes the cause, so it stops the wear getting worse, but it cannot undo wear that has already happened. If the tyre still has safe tread, alignment gives it a longer remaining life. If it is already at the limit, you need both a new tyre and alignment.
If you’ve spotted uneven wear, here’s what to do
You are inspecting properly, which is exactly the right start.
- Compare all four tyres in good light
- Match what you see to the patterns above
- Run your hand across the tread to feel for feathering
- Use the 20p coin test in several places
- Photograph the worst area
- WhatsApp us the photo and your tyre size: wa.me/447955533000
- Driveway diagnosis and replacement in the same visit if needed
- Honest referral to an alignment or suspension specialist if it is not us
- Call us: 07955 533000, 30 to 45 minutes across Scotland, 24/7
Tell us the pattern, and we will know where to start before we arrive.
