Tires: Why the cheapest models can quickly become dangerous

interview

The best car is with bad Tires very quickly at the limit. And a worn tread extends the braking distance in wet conditions by many, many meters. No one wants to experience either situation on public roads. This is exactly what happens every day on the test tracks of the Contidrom near Hanover: Here, the tire manufacturer’s engineers test how tires behave in certain situations all year round and use the results to gain important data for the development of new models. In an interview with stern, Conti test engineer Philipp Must explains why a good tire is better than any insurance – and why going for the lowest price category is often not a good idea.

Mr. Must, especially when shopping online, the cheapest tires are shown first when I search. Can I Germany Buy any model without hesitation?
It is of course tempting to be able to save hundreds of euros on a set of tires. All I can say is that in the world of tires, a blatant difference in price also results in a blatant difference in performance. A cheap tire will never be as safe and good in extreme situations as an expensive model. This is due to many factors. With premium products, the material is of higher quality, the workmanship is better and the know-how is greater. We test our tires down to the smallest detail before they come onto the market. This is incredibly expensive and an investment that manufacturers of so-called cheap tires avoid.

But all tires go through an approval process, don’t they? My understanding is that even the cheapest tires have been declared sufficient by some testing center.
The tires offered here apparently meet the minimum requirements for the European market, yes.

Aren’t these tires sufficient at least for – let’s say – people who don’t drive much?
No, I see it quite differently. Even on a journey that only takes 5 minutes, I have to be able to rely on my tires to handle all weather conditions and all situations as well as possible. Even on a journey from village to village, a dog can jump onto the road – in that case, it would be better if the emergency braking actually brought the car to a quick stop. As I said: the right tires can sometimes make the difference between damage and a moment of shock with no consequences.

Let’s say I need new tires – but I’m lazy. Are all-weather products enough?
An all-season tire is a compromise between the different conditions. It will always perform worse than a good summer tire in summer and worse than a good winter tire in winter. Especially in areas where both seasons are very pronounced, summer tires and winter tires are the most suitable choice. However, it is a suitable alternative for regions with moderate weather conditions all year round and only occasional snowfall.

Do I have to pay attention to special properties when buying tires for electric cars?
There are various markings for electric car tires. Usually this is a stamp with the designation “EV”. These are not completely different models. The different types of drive are actually not that different – at least from the perspective of a tire manufacturer. We do not develop our own tires for electric vehicles, for example. In principle, all vehicles benefit from technological developments.

In the jungle of tire models, new models keep appearing – often with a version number. A kind of continuation. Should you always make sure to buy the latest model?
In principle, you can of course buy an older model if the price difference offers great potential for savings. The age of the tires is much more important than the version number. If the previous model has been in the dealer’s warehouse for three years, I would advise against buying it. Sometimes manufacturers also produce new and old versions at the same time, so you have to see whether you would rather save a little or whether the respective technological advances are worth the money.

What exactly are technological leaps in tires?
It would be strange if a newer model had worse properties than an older one, right? Every tire is continuously developed, which makes the products better and better. I usually get the best performance, whether at the limit of sport or in extreme weather situations, with the new models.

To person

The Contidrom has been around since 1967. Philipp Must hasn’t been on board that long, but the test engineer has been working here since 2008. As a tire expert, he deals with test results and drivers’ test impressions every day. Must knows exactly what a tire has to endure over its long life. He also worked for Continental at the test sites in Texas and Sweden – the tire manufacturer’s two other locations where weather conditions are very unusual for Hanover. Continental operates a total of four test centers, the newest of which is in Hefei, China.

When should I replace a tire?
If in doubt, ask the dealer to point it out during service. In fact, you should check the condition of your tires at least once a year. Simply hold a one-euro coin in the tread. As soon as the gold edge is visible, it’s time. A cheaper tire tread depth gauge would of course be better; you can get one for under five euros.

How does low tread depth affect tires?
Particularly in wet conditions, the properties of the tire change as the tread decreases. If you compare two identical sets of tires, one new and one with the legal minimum tread of 1.6 millimeters, you have to reckon with around 10 meters more braking distance when braking hard with the worn tires on wet roads at 85 km/h. This increases exponentially with speed. At 120 km/h, the braking effect is greatly reduced because the water displacement no longer works as well.

Last but not least: Are you always allowed to repair tires?
You can’t say that across the board, no. Damage to the tread can sometimes be repaired quickly and easily, yes. But not to the sidewall or the sides. Then there’s the tire model: if it’s a model with a high speed index, for example, sometimes you can’t repair it. Basically, every damage is an individual case – and I always recommend going to a professional if possible. They look at the tires with a trained eye and can help. I wouldn’t recommend cheap repair kits for laypeople.