PNEUMATIC TIRE

PROBLEM TO BE SOLVED: To enhance snow performance obtained by enhancing traction characteristics on a snow covered road with dry grip characteristics maintained at a high level. SOLUTION: A tread surface of the pneumatic tire has at least one longitudinal main groove 3 in an outer region 2o facing the outer side of the vehicle. The longitudinal main groove 3 is a rectilinear groove where ridge lines 21 at which groove wall surfaces 20 and the tread surface 2 intersect. Each groove wall surface 20 is composed of an upper wall surface 20U which is gently sloped and extends from the ridge line 21 at an angle θ1 ranging from 40-60° relative to a line normal to the tread surface 2, and a lower wall surface 20L which is steeply sloped and extends up to a bottom surface 22 at an angle θ2 smaller than the angle θ1. The lower wall surfaces 20L each have projections 23 arranged in the tire circumferential direction, while each projection 23 has a triangular cross section with a slope surface 23S extending from the lower end Ue of the upper wall surface 20U up to the groove bottom 22 at an angle θ3 that is not greater than the angle θ1 but greater than the angle θ2. COPYRIGHT: (C)2009,JPO&INPIT