What is the legal minimum tyre tread depth in the UK? +
The legal minimum tread depth in the UK is 1.6mm across the central three-quarters of the tyre, around its entire circumference. However, most motoring organisations recommend replacing tyres at 3mm, as braking performance drops significantly below this level. Driving on tyres below 1.6mm carries a fine of up to £2,500 and 3 penalty points per illegal tyre — so four bald tyres could mean a £10,000 fine and 12 points.
Do I need to replace all four tyres at the same time? +
No, you do not need to replace all four tyres at once unless they are all worn. It is best practice to replace tyres in pairs (both fronts or both rears) to maintain even handling. The newer tyres should always go on the rear axle for stability, even on front-wheel-drive cars. Mixing tyre brands on the same axle is not recommended but is acceptable across different axles.
Should I check my tyre pressures regularly? +
Yes — you should check tyre pressures at least once a month and before any long journey. Under-inflated tyres increase fuel consumption by up to 3%, reduce braking performance, and cause uneven wear that shortens tyre life. Over-inflation reduces grip and causes the centre of the tread to wear faster. Your correct pressures are listed in the vehicle handbook and on a sticker inside the driver's door frame or fuel filler cap.
How do I read my tyre size? +
Your tyre size is printed on the sidewall in a format like 205/55R16 91V. The first number (205) is the width in millimetres, the second (55) is the aspect ratio as a percentage of the width, R means radial construction, and 16 is the wheel diameter in inches. The number after (91) is the load index and the letter (V) is the speed rating. Your vehicle handbook and the sticker inside the driver's door frame show the correct size for your car.
What does the TPMS warning light mean? +
The TPMS (Tyre Pressure Monitoring System) warning light indicates that one or more of your tyres has dropped below the recommended pressure. This could be caused by a slow puncture, a change in temperature, or simply natural air loss over time. Do not ignore it — under-inflated tyres increase braking distances and can overheat at speed. Check your pressures at the nearest petrol station or call a mobile tyre fitter.
What happens during an MOT tyre check? +
During an MOT, the examiner checks that all tyres are the correct size and speed rating for the vehicle, that tread depth is at least 1.6mm across the central three-quarters, that there are no cuts, bulges, or exposed cords, and that tyres on the same axle are of the same type (e.g. not mixing radial and cross-ply). Incorrect tyre pressure is not an MOT failure but the examiner may issue an advisory.