What are Winter Tires?
In many countries there is a duty to use Winter Tires at certain times or road condition which could be ice, snow mud or smoothness.
Winter Tires are supposed to be used with wintery road conditions and low temperatures. They have a rubber compound which is enough elastic with low temperature to achieve a sufficient gearing and transmission with the underground.
Winter Tires are always marked with the M+S Symbol (Mud and Snow). The EU regulation nr.661/2009 dated from the 13th July 2009 declares M+S marked tires as tires which above all have a tread profile, tread compound and constitution in order to achieve better driving and traction qualities on snow.
Another symbol for Winter Tires contains a mountain and a snowflake (Alpine Symbol) and is always awarded from the American Road Service NHTSA.
Unlike summer tires, winter tires in addition to their normal profile have slats which make it possible to get a gearing on loose underground like snow.
When the temperature drops below 45°F the rubber compound of a summer tire begins to harden. In contrary to that the rubber compound of a winter tire contains a higher percentage of natural rubber so it is able to retain its elasticity.
A lot of different test have shown that even when travelling at the low speed, a winter tire can stop up to 11 meters shorter on icy roads than a normal tire at wintry weather condition below 45°F.