PNEUMATIC TIRE

摘要

A pneumatic tire having enhanced snow performance obtained by increasing traction characteristics on snow covered road with dry grip characteristics maintained at a high level. The tread surface (2) 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) and a lower wall surface (20L). The upper wall surface (20U) is gently sloped and extends from the ridge line (21) at an angle ?1 ranging from 40° to 60° relative to a line normal to the tread surface (2). The lower wall surface (20L) is steeply sloped and extends up to a bottom surface (22) at an angle ?2 smaller than the angle ?1. The lower wall surfaces (20L) each have projections (23) arranged in the tire's circumferential direction. 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 ?3 that is not greater than the angle ?1 but greater than the angle ?2.