Tyre Safety & Maintenance
Cracked or Perished Tyres: When Must They Be Replaced?
Small cracks do not all mean the same thing. This UK guide explains when a tyre needs professional inspection, when it must be replaced, and what MOT testers actually check.
The quick answer
Stop using the vehicle and arrange tyre replacement if you can see exposed cord or ply, a lump or bulge caused by structural damage, tread separation, rapid pressure loss, or a deep sidewall cut. Fine surface cracking is not automatically an MOT failure, but it is a sign of ageing and should be assessed by a qualified tyre professional. If you cannot judge the depth or condition safely, do not guess.
Tyre rubber changes with age and exposure. Cracking may appear on the sidewall or inside the tread grooves, especially on spare wheels, caravans, trailers and vehicles that are used infrequently. The location, depth and surrounding damage matter more than the appearance of one isolated line.
Do not drive on a tyre with exposed cords, a structural bulge, tread lifting or rapid air loss. Move away from live traffic only if it is safe to do so, then call for professional help. TMA provides 24-hour emergency tyre fitting in Bolton and surrounding areas.
What does “perished tyre” mean?
A perished tyre is one whose rubber has begun to deteriorate. Age, ultraviolet light, ozone, temperature, storage conditions and operating conditions can all contribute. The rubber may harden and show cracks or crazing on the sidewall or in the tread grooves.
The British Tyre Manufacturers’ Association explains that tyre ageing is not caused by time alone. Infrequently used tyres can be especially vulnerable because normal flexing helps protective additives move through the rubber. This is why a low-mileage spare, trailer tyre or caravan tyre can still deteriorate.
Needs inspection
Fine surface crazing
A network of shallow-looking lines can be an early sign of ageing. It is not automatically an MOT failure, but a photograph cannot confirm the crack depth or internal condition. Arrange a professional inspection.
Replace urgently
Exposed cord, bulge or separation
Visible reinforcing material, a structural lump or bulge, or lifting tread indicates serious damage. Do not continue driving. Arrange recovery or mobile replacement.
High concern
Deep sidewall cracks or cuts
The sidewall repeatedly flexes in use. A deep cut or split may compromise the casing and is not suitable for a normal puncture repair. Have it assessed without delay.
Check the cause
Cracking with pressure loss
A tyre that repeatedly loses air may have damage at the tread, valve, bead, wheel or casing. Repeatedly topping it up is not a repair and can hide a developing fault.
When should a cracked tyre be replaced?
Use this as a safety guide, not as a home MOT test. Proper inspection may require the tyre to be removed from the wheel so its internal condition can be checked.
| What you find | What it may mean | What to do |
|---|---|---|
| Fine, shallow-looking surface crazing | Ageing or environmental exposure | Book a qualified inspection and monitor all tyres |
| Deep sidewall cut, split or extensive cracking | Possible casing damage or advanced deterioration | Avoid unnecessary driving and arrange urgent assessment |
| Ply or cord visible | Structural layers are exposed | Do not drive. Replace the tyre. |
| Lump, bulge or tread lifting | Separation or partial failure of the structure | Do not drive. Arrange professional help. |
| Cracking plus repeated pressure loss or vibration | Possible tyre, valve, bead or wheel fault | Stop and have the complete assembly inspected |
Will cracked tyres fail an MOT?
Cracking alone is not an automatic MOT failure. The official MOT inspection manual tells testers to reject a tyre when ply or cord is visible, including where exposed material is revealed by carefully opening a cut. It also gives a failure threshold for a larger cut where cord can be felt, and it rejects lumps, bulges or tears caused by structural separation or partial failure.
Minor-looking surface crazing may pass or receive advice, depending on its condition. An MOT pass is only a judgement at the time of the test. It does not guarantee that an ageing tyre will remain serviceable for the following year.
You can read the current GOV.UK MOT tyre inspection criteria. If you are unsure, have the tyre examined before the test rather than relying on appearance alone.
How to check tyres for ageing and cracking
- Park safely.
Use level ground, switch off the engine and make sure you can inspect the vehicle away from moving traffic. - Look at both sidewalls.
Check the visible outer face and the inward-facing side where access allows. Do not crawl under an unsupported vehicle. - Inspect the tread and shoulders.
Look for cracks in the grooves, embedded objects, lifting rubber, uneven wear and other damage. - Check for lumps and bulges.
A suspicious deformation needs assessment by a tyre specialist because it may indicate internal damage. - Check cold pressure.
Use the vehicle manufacturer’s specified pressure. A repeated drop needs diagnosis, not repeated topping up. - Find the manufacture code.
The final four digits of the tyre’s date marking show the week and year of manufacture. For example, 2219 means week 22 of 2019. The code may appear on only one sidewall. - Inspect every tyre.
If one same-age tyre is deteriorating, check the others and the spare. Caravans, trailers and little-used vehicles deserve particular attention.
For help reading the markings, see TMA’s guide to tyre sidewall codes. For cuts, bulges and impact damage, read the detailed tyre sidewall damage guide.
How old is too old for a car tyre?
There is no single universal age limit that decides whether every car or van tyre is serviceable. The BTMA says operating conditions and environmental exposure vary too widely for one limit to apply to every tyre. It also notes that some manufacturers recommend withdrawing car or van tyres from service once they are over 10 years old.
Michelin recommends replacement as a precaution if a tyre has not been replaced 10 years after its manufacture date, including a spare. Always follow the tyre manufacturer’s advice, the vehicle handbook and the judgement of a qualified professional. Condition can require replacement much earlier than any age threshold.
The 10-year legal restriction often mentioned online does not apply to ordinary car tyres in the same way. UK age restrictions apply to specified wheel positions on certain heavy vehicles, buses, coaches and minibuses. For cars and vans, condition and manufacturer guidance remain essential.
Can a cracked or perished tyre be repaired?
Ageing rubber cannot be restored with glue, sealant or tyre dressing. A professional puncture repair may be possible only where the puncture is in the permitted repair area and the complete tyre remains structurally sound. A sidewall cut or puncture is not a normal repair candidate.
Do not use cosmetic products to hide cracking. BTMA says claims that sidewall dressings improve resistance to UV light or ozone are unproven, and repeated use of some solvent-based products may contribute to premature surface cracking. Michelin also advises avoiding unsuitable sidewall cleaning products.
How to reduce premature tyre deterioration
- Check cold tyre pressures at least monthly and before long journeys.
- Inspect tyres monthly for cracks, cuts, bulges, embedded objects and abnormal wear.
- Follow the vehicle’s load limits and tyre-pressure instructions.
- Avoid kerb impacts and have tyres checked after a severe pothole strike.
- Store loose tyres in a cool, dry place away from direct sunlight and contaminants.
- Give extra attention to spares, caravans, trailers and vehicles used infrequently.
- Use only suitable cleaning products and never apply dressing to the tread.
What should you do if you spot dangerous tyre damage?
If the vehicle is parked safely, leave it parked and arrange inspection or replacement. If a problem becomes apparent while driving, reduce speed smoothly and stop in a safe place as soon as you can. On a motorway or other high-speed road, follow the Highway Code breakdown guidance. Do not attempt a repair where you or the fitter would be exposed to live traffic.
When contacting TMA, send your exact location, vehicle registration, tyre size and clear photographs of the damage. Availability, price, safe access and a realistic arrival estimate can then be checked before dispatch.
Unsure whether your tyre is safe?
Call or WhatsApp TMA Mobile Tyres with your location, registration, tyre size and clear photographs. We provide mobile tyre assessment and replacement across Bolton and surrounding areas, subject to stock, technician availability and safe access.
Cracked and perished tyre FAQs
Are small cracks on a tyre dangerous?
Fine surface cracking is not automatically dangerous or an MOT failure, but it shows that the rubber is ageing. The crack depth, location, tyre age and any pressure loss or deformation must be considered. Arrange professional inspection if you are unsure.
Will a perished tyre fail an MOT?
It depends on the defect. A tyre will fail where ply or cord is exposed under the criteria in the MOT manual. Structural lumps, bulges, tears and certain larger cuts also fail. Superficial crazing is not an automatic failure.
Can a cracked tyre sidewall be repaired?
A sidewall cut or puncture is not suitable for a normal puncture repair, and ageing rubber cannot be restored. A qualified tyre professional should assess the tyre and replace it when the condition is unsafe.
What does tyre perishing look like?
It often appears as fine cracks or crazing on the sidewall or inside the tread grooves. Advanced deterioration may include deeper splits, repeated pressure loss, vibration or deformation.
How do I read a tyre’s age code?
The final four digits of the date marking show the production week and year. For example, 2219 means the tyre was manufactured in week 22 of 2019. The complete marking may be on the inward-facing sidewall.
Should car tyres be replaced at 10 years old?
Some manufacturers recommend withdrawing car or van tyres from service after 10 years. Michelin recommends replacement at 10 years as a precaution. A tyre may need replacement much earlier because of its condition, use or manufacturer guidance.
Can I drive to a garage with a cracked tyre?
Do not drive if cords are exposed, the tyre has a structural bulge, tread separation, rapid air loss or other serious damage. If the condition is uncertain, arrange mobile assistance or professional advice rather than taking a risk.
Why do low-mileage tyres perish?
Ageing also depends on UV light, ozone, storage and operating conditions. Tyres on vehicles used infrequently can deteriorate because the protective additives in the rubber do not circulate as effectively through normal flexing.
Safety information used in this guide
This guide reflects the current GOV.UK MOT inspection manual, BTMA motorist tyre-care guidance, TyreSafe inspection advice and Michelin tyre-age guidance. Always follow the instructions for the specific tyre and vehicle.