It’s a good question. Many people are only prompted into a tyre change when their rubber is illegal. But a tyre’s ability to keep us safe starts deteriorating long before then.
How long should a car tyre last for?
A car tyre should last for around 20,000 miles. But there are variables to consider. A front tyre will wear quicker than a rear because it has the weight of the engine over it and must steer too. If you’re an aggressive driver, your tyres will wear down quickly. And if you do a lot of motorway miles, the increased temperatures will cause faster wear. Tyres that are run under the correct recommended pressure will wear more rapidly too.
When the tread depth is illegal
Car tyres start off with around 8mm of tread. The legal minimum is 1.6mm of tread over three quarters of the treaded area. However, safety experts recommend that tyres are changed when their tread gets down to 3mm. That’s because there’s a significant drop-off in wet braking performance the more tyres wear down towards the legal minimum. If you don’t believe us, this film from Continental demonstrates the difference between 1.6 and 3mm pretty graphically.
When the tyre is damaged
Tyres lead a hard life. And the UK’s potholed streets don’t help. When tyres hit a pothole or bash against kerbs, their internal structure can be damaged. When the metal cords that give the tyre its strength fail, lumps can appear in them. Equally, sharp objects can cause damage to the tyre’s vulnerable tyre wall. Any damage like this makes them an instant MOT failure. It’s easy to check for lumps like these and the simple video below shows you how.
When the tyre is too old
We tend not to think of tyres ageing but they most certainly do. The oils used in the compound of materials that make up the ‘rubber’ need to be moved around to keep the tyres supple. If a tyre isn’t used much and is exposed to sunlight, the UV rays can cause the rubber to crack.
You can find out how old a tyre is by looking on the side wall. There you will find four numbers, usually preceded by the letters DOT. Those four numbers are the week in the year and the year that the tyre was manufactured. So, 1715 is the 17th week of 2015.
There is no particular rule about how old tyres should be before they’re replaced. And they normally wear out before age comes into play. But if you don’t do many miles, do keep an eye on your tyres. And once they get older than five years, it’s worth keeping a close eye on them.