Overview
- Under‑inflated tyres are flagged as a potential MOT fail, with drivers urged to monitor pressures for safer braking, handling and even wear.
- Minimum legal tread depth is 1.6mm, and outlets relay the 20p coin test as a quick way to spot tyres that fall below the limit.
- Bulges or cuts on sidewalls indicate structural damage that can trigger a fail, with immediate replacement recommended by the guidance.
- Deep cuts or any exposed cords or ply in the tread or shoulders lead to an automatic fail and require the tyre to be replaced at once.
- MOT checks include TPMS functionality where fitted and compliance on tyre size matching per axle plus required speed (at least 70 mph) and load ratings, with reports also noting possible insurance consequences for defective tyres.