Code Breaker

For many drivers, the sidewall of a tyre is a mystery. They may be able to spot the manufacturer’s name and the model, but beyond that, the rest of the information means nothing. Even when they have copied down the size of the rubber to ring round for prices, owners are often in the dark about what the numbers represent.

So here we explain the mass of detail contained on every sidewall, from the cheapest import to the industry’s top names. Our guide will not only help you when it comes to replacing your tyres, but also to check that the ones you’re running are right for your car and in good condition.

This is key if you did not buy the tyres, as their life is not only limited by wear. Age is also a factor; the compounds used deteriorate, and performance tails off as a result.

Any tyre more than five years old should be looked at carefully. How do you know how old yours are? Our walkthrough reveals all.

Up CloseThere's no standard mark for run flat tyres - which can be used for about 50 miles without pressure - so check model name

Also, keep an eye out for the part warn mark; any rubber bought second-hand should be stamped accordingly.