To improve a performance on snow while securing a performance as a summer tire.
In a shoulder block 30, a lateral sub groove 32 extending from the vicinity of the inner side of the tire width direction of the ground end 12E toward the outer side of the tire width direction is formed, and the height of the outer surface in the tire radial direction of the outer part of the ground end is different at the sides of a lateral groove 28. During a drive on snow, the outer part of the ground end is buried in snow, so that the snow column shearing force by the lateral sub groove 32 is obtained. Further, in the shoulder block 30, since the height of the outer surface in the tire radial direction of the outer part of the ground end is different at the sides of the lateral groove, irregularities are formed on a tread surface of the outer part of the ground end. During a drive on snow, snow enters in a recessed part of the tread surface of the outer part of the ground end, so that the column shearing force is obtained. Accordingly, the performance on snow can be improved. The lateral groove 32 does not cross through the shoulder block 30, the rigidity of the shoulder block 32 will not be lowered, thereby ensuring the performance as a summer tire.
Kato Kazunori
Katsuichi Nishimoto
Hiroshi Fukuda