Abstract: A pneumatic tire for a passenger car wherein a plurality of grooves are disposed on a tread surface to define and form land portions, and kerfs which are open to the grooves at at least one of the ends thereof are disposed on the land portions. At least one stage of step portion is disposed in a step shape on at least one of the groove walls of the grooves, and a plurality of kerfs are disposed on the step portion with smaller gaps than those of the kerfs disposed on the land portions.

Abstract: A pneumatic radial tire has a tread pattern having a pair of straight main grooves each having a width equal to 8-13 percent of a ground contact width W of the tire and extending in parallel on opposite sides of an equator of the tire, a plurality of lug grooves extending across shoulder regions formed on the outersides of the pair of main grooves from the pair of main grooves outwardly toward the ends of the ground contact surface of the tire to form in cooperation with the main grooves successive rows of blocks, and a plurality of V-shaped sub-grooves in the shoulder regions spaced at a predetermined pitch apart in the circumferential direction of the tire and extending divergently with respect to the direction of reverse rotation of the tire, wherein the ratio of a distance W1 between respective centers of the main grooves to the ground contact width W is in the range of 0.2.ltoreq.W1/W.ltoreq.0.4; an angle .alpha.