Abstract: A pneumatic radial tire for passenger car has a directional tread pattern comprising many blocks formed in a tread portion by a plurality of circumferential grooves extending in a circumferential direction of the tire and a plurality of directional slant grooves obliquely extending with respect to the circumferential direction, wherein at least a part of the directional slant grooves is branched from the circumferential groove near to the pattern center and extends toward and is opened at an end of a ground contact region of the tread, and at least a part of corner portions of each of the blocks forms an acute angle of 10-60° defined by the circumferential groove and the directional slant groove; and a surface of the corner portion of the block having an acute angle of 10-60° is beveled over a distance of 10-30 mm from a tapered end thereof in a longitudinal direction so as to gradually shallow from the tapered end toward a width widened portion of the block in both stepping-in and kicking-out sides o

Abstract: A pneumatic tire in which a foamed rubber layer having closed cells is provided at a surface of a tire tread which substantially contacts at least a road surface, wherein the foamed rubber layer has closed cells whose average diameter is about 1 m to about 120 m and has an expansion ratio of about 1% to about 100%, a solid-phase rubber portion of the foamed rubber layer has a rubber composition in which at least both of a diene-type rubber and silica are mixed, and an amount of the silica is about 10 to about 80 parts by weight based on 100 parts by weight of the diene-type rubber. The pneumatic tire exhibits excellent traction and braking abilities and controllability on snowy, icy and wet road surfaces.