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.
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 are run-flat tyres and can any fitter work on them? +
Run-flat tyres have reinforced sidewalls that support the weight of the car even with no air pressure, allowing you to drive up to 50 miles at 30mph after a puncture. They require specialist fitting equipment and a TPMS reset after replacement. Not all garages can work on run-flat tyres, but most professional mobile fitters and tyre centres are fully equipped. Run-flat tyres are typically 20–40% more expensive than standard equivalents.
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.
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.
How long does it take to fit a new tyre? +
A single tyre change typically takes 15 to 30 minutes, including removing the old tyre, fitting and balancing the new one, and torquing the wheel nuts to the correct specification. If you are having all four tyres replaced, expect the job to take around 45 minutes to an hour. Mobile fitters work to the same timescales as a garage.