News

 

Winter tyres on a wet surface – braking distance shorter by two car lengths

We’re debunking myths – how to successfully stop the car during this autumn and winter’s rainy weather

Numerous tests[1] that had been carried out leave no doubt: a car equipped with winter tyres, driving on a wet surface at a temperature around 2-6ºC, will come to a stop faster than a vehicle with summer tyres. It should be noted, that a typical automobile under hard braking loses most of its speed in those lasts few metres before it stops completely – it is not difficult to figure out that winter tyres will stop the car before it hits an object in its way, while a car on summer tyres will crash into it with a large momentum. What if the thing that is in the way turns out to be a pedestrian? Unfortunately, the pedestrian’s chances of surviving such accident are immensely low. Driver’s skill set is hardly the issue – the laws of physics are ruthless.

The  tests of winter tyres[2], carried out and filmed by Auto Express, confirm the difference in performance between winter and summer tyres on a  wet road, at a temperature of 6ºC: the braking distance of a car driving on summer tyres was longer by as much as 7 meters. The most popular vehicles have the length of a little over 4 meters. At the point in which the car with winter tyres stopped, the car with summer tyres was still travelling at 32 km/h.

„This is precisely why in such weather as we’re experiencing right now, when it often rains and the mornings are quite cold, good winter or all-season tyres with winter homologation are the guarantee of a safe journey. The 20-30 cm advantage in braking distance of summer tyres on a dry surface in the morning means very little, if not nothing, considering that later that evening the road on the way home may be wet and then the braking distance elongates by more than our car’s length. How many of us, like F1 drivers, change their tyres a couple of times a week? Modern winter tyres made by reputable manufacturers provide safety in a wide range of weather conditions – they are effective even at a temperature around 10-15ºC on a dry road, but also on wet surfaces, when it gets chilly and all through serious winter. The longer you wait to change to winter tyres, the more you put your life at risk. Your life and the lives of others. Such difference in braking distance is a matter of life and death for a pedestrian. Don’t run that risk by postponing your visit to the auto service and letting yourself be guided by myths about winter tyres. When the weather gets bad, you may not even get there” – says Piotr Sarnecki, Director General of Polish Tyre Industry Association.

The use of winter tyres has a positive impact on braking and traction[3]. Tests comparing summer tyres to the winter type[4] show us just how much tyres well suited to the temperature, wetness and slipperiness of the surface help the driver to control the vehicle. Every driver who has ever skidded knows just how difficult gaining full control over a car is, which regardless of all security systems, has almost no traction. A skid is quite unpleasant in itself, but if we think about the fact that we’re hardly ever alone on the road, it becomes a real threat to our life and the lives of others. To avoid serious accidents or collisions, experts recommend driving on homologated winter tyres until spring – their effectiveness is based on nothing but utilisation of physics and chemistry for our specific needs – driving safety enhancement. The Report of European Commission proves that the use of winter tyres reduces the risk of an accident by 46 percent[5].

The rubber compound used in winter tyres consists of more natural rubber and silica, thanks to which it does not harden in low temperatures. A special winter tread pattern allows the water to drain away faster, grips on snow and thanks to spacious, self-locking sipes it also ensures safety on dry roads. The rubber compound as well as the tread are key elements that increase traction and thus shorten the braking distance[6].

Homologated winter tyres, that is those with the so-called Alpine symbol[7] - the three-peak mountain and a snowflake symbol, give us a much larger security margin, that is shorter braking distance, which often mitigates the risk of an accident and saves lives. Summer tyres start to harden when the temperature drops to 7-10°C and their braking distance elongates considerably compared to the braking distance of winter tyres – the difference can be as big as 10 meters, that is two lengths of a big car. You should never skimp on safety. The commonly encountered M+S symbol only denotes tyres with a tread for mud and snow, and is given by the manufacturers in a virtually discretionary fashion. The M+S symbol alone, without the company of the Alpine symbol, does not denote neither the winter tyre nor the all-weather one, as it has not been granted the winter homologation.

„Rumour has it that winter tyres are an additional burden to our household budgets, but is it true? If we assume that our annual mileage is 20 000 km, then in 5 years it will increase by 100 000 km. During this time period, we will wear out two sets of tyres - regardless of whether they’re two sets of summer tyres or one set of summer and one of winter tyres. Separate sets of summer and winter tyres allow for a decrease in the wear of each set, because they are only used for half a year. But driving on summer tyres during the summer and a different set during the winter is, first and foremost, a matter of maximal increase of our safety. It would be much cheaper for manufacturers to produce just one type of tyres, but unfortunately physics cannot be deceived –one type of tyre perfect for all weather conditions does not exist. Some drivers decide to put all-season tyres into practise. Of course, if we use them, we don’t have to schedule appointments twice a year at our local car services and we’re able to save some money on tyre change, but our savings will soon be spent on new sets of tyres. Why is that? All-season tyres are used all year round, regardless of weather conditions. Their wear especially increases during the summer, which is due to their softer rubber compound, compared to that of summer tyres. It’s true that from year-to-year they’re more and more polished, but all-season tyres will always lose the battle of performance to dedicated summer and winter tyres. Even the best all-season tyres won’t be as good as the best summer tyres or perform as well as winter tyres do during the winter. Nonetheless, if somebody still plans to drive on only one set of tyres and mainly in a city, then all-season tyres are a much better choice than summer tyres” – adds Piotr Sarnecki.

It is important to note the latest change in drivers’ attitude - 78% of them are in favour of  introducing a requirement of driving on winter or all-season tyres with winter homologation[8] – such legislation was introduced and is applied in 26 countries in Europe. The growing awareness of Polish drivers gives us hope for an increase in the number of people driving on winter or all-season tyres in the winter – now one-third of them puts themselves and others at risk while driving on summer tyres in the winter. We appeal to every driver – it is better to change to winter tyres even a few days too early than one day too late.

Source: Polish Tyre Industry Association

 

Home |  News |  Publications |  Media |  About |  Contact

Created by HyperWeb