What tyres fit my car?

• The door pillar. A sticker on the driver’s door pillar often shows the size and the correct pressures.
• The fuel flap or glovebox. Some cars put the sticker there instead.
• The tyres themselves. Look at the sidewall. If you bought the car second hand, the previous owner may not have fitted the right size, so check against another source.
• The handbook. If you do not have a printed copy, you can usually find one through the manufacturer or online, even for older models.
• Your registration. A registration lookup can suggest the size, but always check it against the handbook.
• The vehicle documents. The certificate of conformity (CoC) lists the recommended size, and any alternatives.

For sizing you only need six markings: the width in millimetres, the sidewall height as a percentage of the width, radial construction, the rim diameter in inches, the load index (the most weight the tyre can carry) and the speed symbol (the top speed it can carry that load at). The full guide is how to read your tyre sidewall.

Two simple rules when choosing replacements. First, match the size, load index and speed rating the tyre or vehicle manufacturer recommends. Second, never go smaller, or to a lower load capacity, than the original specification.

Only within the tyre, wheel and vehicle manufacturers’ recommendations and the law. If the combined tyre and wheel diameter is wrong, the speedometer reading and ride height can change. Always check with the manufacturer first: driving on unapproved sizes risks accidents and fines.

If you change the wheel size, you can change the tyre size so long as the overall diameter stays the same. The speedometer may need recalibrating and the pressures adjusting.

Not on the same axle. The tread pattern is designed to clear water and debris, and different patterns on one axle put uneven stress on the whole system, causing uneven wear and less grip in the wet or on loose ground.

Never mix bias-ply and radial tyres on a vehicle, except in an emergency.

Once you have the size, decide the type: summer, winter or all season, wet braking performance and budget. Our guide to what tyres do I need takes you through it, or call us and we will help you choose.