Bulge in a Tyre: Is It Safe to Drive?
A bulge or bubble in the sidewall is a sign the tyre's internal structure has failed. The air is pushing against only the outer rubber, so the tyre can burst without warning. A tyre with a bulge should not be used.
What causes a tyre bulge
- Hitting a pothole, kerb or other hard edge at speed
- Driving over debris
- Running at low pressure, which flexes the sidewall
- A manufacturing fault, which is rare
Can it be repaired?
No. Tyres cannot be safely repaired in the sidewall, and a bulge cannot be fixed. The tyre must be replaced.
What to do
- Slow down and avoid motorways or long journeys.
- If the car has a spare, fit it, or arrange a mobile fitter to replace the damaged tyre.
- Do not keep driving on it to get to a garage if you can avoid it.
Is it an MOT failure?
Yes. A bulge, cut or other sidewall damage that exposes the structure is a dangerous defect and will fail an MOT, and driving with it can put you at risk of prosecution.
Check the whole tyre
Look at the inner sidewall too, which is harder to see. Run your hand around the tyre, carefully, and feel for lumps. If you find one, call us on 0800 772 0355 and we will bring a replacement. Our emergency tyre fitting covers this. Also see what to do with a flat tyre.