To wear out or not to wear out completely: when should you change your tyres?

A premium tyre driven down to the wear limit can brake better on wet roads than a brand-new low-cost tyre. For this reason, Michelin is asking for the label to also include measurements taken with used tyres.

Today, the mandatory label for new tyres is one of the tools consumers have to assess and compare performance when buying tyres.

Here we explain the keys to correctly interpreting the tyre label, based on the three parameters it provides information on: rolling resistance, wet braking and noise level. The point is that this information applies to the tyre when it is new. And, of course, as soon as you fit them to your car and leave the workshop, the tyre starts to wear.

A tyre’s performance changes as the depth of its tread decreases. For example, with wear, dry braking and fuel consumption normally improve. But wet braking worsens noticeably.

The legal wear limit for knowing when tyres must be replaced is 1.6 mm. This is something they check especially during the tyre inspection at the ITV (MOT) test. And it has always been said that, for safety, it is best not to push tyres down to that limit.

Michelin is asking for the label to include tests with used tyres

Some manufacturers even recommend replacing tyres much earlier, when they reach 3 mm of tread, especially if you are going to drive in the rain. But with its “Long Lasting Performance” (LLP) strategy, which roughly translates as “Performance to the last kilometre”, Michelin has spent several years showing us that this is no longer always the case… depending on which tyres your car is fitted with.

Michelin estimates that the total saving for European motorists if tyres that guarantee safety down to the legal wear limit of 1.6 mm were used could reach 6.9 billion euros a year, saving up to 128 million tyres a year in Europe that would not have to be replaced prematurely.

In 2017 I was able to attend some interesting test days at Michelin’s Ladoux Test Centre, which have been repeated recently. The results were presented in Vienna in early July. And they do nothing but confirm those first tests: on wet asphalt, a car with premium-brand tyres worn down to 1.6 mm of tread can stop up to 3.4 metres shorter than when fitted with brand-new tyres from a “low-cost” manufacturer.

What is more, I still remember how in those tests, on a skid pad, the car with brand-new “cheap” tyres lost grip at a speed clearly lower than the car with worn tyres from recognised brands. And with a considerable layer of water on the asphalt. Here are some recent, very revealing videos

Video: The secrets of grip

Video: wet braking, premium vs low-cost tyre

So what does Michelin say about this? That the absence of regulations governing the minimum performance a tyre must meet as it wears is a problem for safety, for your wallet and for the environment.

It makes sense. If your car’s tyres guarantee your safety even when worn down to the wear limit, then, in addition to the safety factor, which alone already justifies choosing quality tyres, the economic factor comes into play: you can change your tyres later.

Should I therefore run tyres down to the wear limit?

Well, until the tyre label includes the result of the wet braking test that Michelin is asking for, which would let you choose, compare and decide for yourself, my answer is yes… but only if your car has tyres from a recognised brand.

Related information

–How to check your tyre wear and avoid fines
–Five tips for keeping your tyres in good condition
–Budget vs premium tyre comparison: danger on the road!
–Is it worth inflating tyres with nitrogen?