Winter 4x4 tyre kennzeichnungen ms snowflake symbol tyre width 235 mm tyre cross section 55 rim diameter 18 inch load index 100 up to 800 kg speed rating t up to 118 mph rim protector rolling resistance f wet grip f noise emission 72 db noise classification nc 2 installation all round tyre sipe unidirectional tread customer benefits equal grip distribution main strength high traction