Even this year we are approaching the moment when it is advisable for many drivers to mount winter tyres. Many motorists, however, have the confused ideas about tyres to be installed in winter on their vehicle. Let us therefore make clear.
What are the peculiar characteristics of winter tyres?
There are two. The first is the tread compound, which, unlike normal tyres, keeps the elastic even at low temperatures, thus ensuring better adhesion (hence the term “thermic” for winter tyres); the second one is the tread pattern, full of blades clinging to the snow. These two factors mean that when the temperature drops below 7 ° C, winter tyres have better summer performances not only in the snow, but also in the wet.
How do winter tyres stand out?
For the Code, because the tyres are considered winter, it is enough to have M + S (Mud + Snow, mud and snow) marking. However, it alone is not a guarantee of good winter performance. The presence of the “snow flake” (or, more correctly, 3PMSF – Three Peak Mountain Snow Flake, a symbol of a snowflake enclosed in a mountain profile, certifies that the tyre has passed specific winter tests and is a winter tyre of good standard.
Although winter tyres may have the same thickness value as the summer tyre tread, or 1.6 mm, the adherence to the snow falls drastically when the tread thickness falls below 4 mm, so it is good to replace them when they reach this threshold.
What is the duration of a winter tyre?
With regard to their durability, winter tyres keep good performance even after a few years. However, the compound undergoes a slow aging which partially reduces adherence.
What is the right time to fit winter tyres? And when is it good to go back to summer?
There is no rule for everyone, because they count environmental and weather conditions as well as the use of the car. However, apart from the obvious observation of any local ordinances, it is good to go to winter tyres in late autumn and return to summer when the temperature exceeds steadily 15 ° C. In this regard, let’s remember that it is wrong and counter-productive to use winter tyres when it is hot, because in such conditions the summer’s performance is definitely better and the winter tread wears very quickly.