A heavy duty pneumatic tire in which occurrence of uneven wear is inhibited is provided. In the tire, each shoulder land portion includes a groove wall portion forming a wall of a shoulder circumferential groove, and a cap portion located outward of the groove wall portion in an axial direction. A wear resistance index of the groove wall portion is lower than a wear resistance index of the cap portion. A ratio of a distance in the axial direction from an outer edge of the shoulder circumferential groove to a boundary between the groove wall portion and the cap portion on an outer surface of the shoulder land portion, to a width in the axial direction of the shoulder land portion, is not less than 20% and not greater than 30%.

A tire includes a tread having a shoulder region, a shoulder transverse groove being fixedly set in the shoulder region, and a shoulder block row configured by aligning the shoulder blocks in a tire-circumferential direction, in which the shoulder transverse groove has an angle formed by a groove wall and a vertical line drawn from a groove opening end position to a tread surface of the shoulder block within a range of 10 to 20 degrees, and the groove wall and groove bottom are connected by a concave surface with a radius of curvature of at least 6 mm and no more than 15 mm.

A tire having a circumferential groove having a groove bottom and a pair of groove walls. The groove bottom is provided with groove bottom raised portions protruding radially outwardly from a reference plane 5a. The groove bottom raised portions are a first groove bottom raised portion located on a first side in the width direction of the circumferential groove and a second groove bottom raised portion located on a second side in the width direction. The first and second groove bottom raised portions each has a plurality of repeating units having a first bottom surface extending substantially in the tire radial direction and a second bottom surface inclined with respect to the tire radial direction at a larger angle than the first bottom surface. The inclination direction of the second bottom surfaces of the first groove bottom raised portion is opposite to the inclination direction of the second bottom surfaces of the second groove bottom raised portion.

A pneumatic tire comprises in a tread surface thereof a land portion that comprises a plurality of blocks. Each of the blocks comprises in a contact patch thereof a plurality of narrow shallow grooves and a plurality of recessed portions disposed separated from the narrow shallow grooves. The narrow shallow grooves have a groove width of from 0.2 mm to 0.7 mm and a groove depth of from 0.2 mm to 0.7 mm. The recessed portions have the same depth as the narrow shallow grooves.

A heavy duty pneumatic tire includes a tread portion provided with at least one circumferentially extending main groove, at least one circumferentially extending sub groove, and a plurality of lateral grooves to form repeated pitch elements each of which consists of one lateral groove and a block element. The sub groove includes a shallow bottom part with a depth smaller than that of the main groove. The shallow bottom part of the sub groove is provided with a groove bottom sipe. The lateral grooves include a shallow bottom part with a depth smaller than that of the main groove. The shallow bottom part of the lateral groove is provided with a groove bottom sipe. The lateral grooves have groove widths W2 in a range of from 5% to 15% in relation to a circumferential length L1 of the pitch element.

The pneumatic tire has main grooves; land portions which are sectioned by the main grooves; paired notches which face to each other as well as being open to a tread surface; the notches being concave portions which are formed in side surfaces of two land portions which are adjacent across the main grooves; tie bars which protrudes at a predetermined height from groove bottoms of the main grooves and connect between the paired notches; and dimples which are provided in the middle in a width direction of the tie bars. The dimples are arranged at least in a notch internal region which is surrounded by wall surfaces of the notches among the tie bars.

A circumferential groove has a groove bottom and a pair of groove walls. Groove bottom includes groove bottom protruding portions protruding radially outwardly from a groove bottom reference surface and having a first groove bottom surface extending radially. The first groove bottom surface includes a first surface portion on one side of a center line of the circumferential groove and a second surface portion positioned on the other side, and an angle between them is 20° to 170°. The groove wall includes groove wall protruding portions protruding toward an inside of the circumferential groove from a groove wall reference surface defined as a circumferential surface at a widest groove width position of the circumferential groove and having a first groove wall width surface 12 extending in a tyre width direction and a second groove wall surface having an angle larger than the first groove wall width surface.

A groove bottom is formed symmetrically about a center line of a circumferential groove in a tread plan view and includes groove bottom protruding portions protruding radially outwardly from a groove bottom reference surface parallel to a tread surface at a deepest position of a groove depth. Groove bottom protruding portions have a first groove bottom surface extending radially and a second groove bottom surface having an angle larger than the first groove bottom surface. Groove walls include groove wall protruding portions protruding toward an inner side of the circumferential groove from a groove wall reference surface as a circumferential surface at a widest position of a groove width. The groove wall protruding portions each has a first groove wall width surface and a second groove wall surface having an angle larger than the first groove wall width surface.

A pneumatic tire includes a plurality of main grooves each extending in a tire circumferential direction, and a shoulder rib formed by a shoulder main groove included in the main grooves. The shoulder rib is formed in an outer part of the pneumatic tire in a tire width direction. The shoulder rib includes a closed slit that communicates with the shoulder main groove and ends in the shoulder rib. The shoulder main groove includes a protrusion that extends into the closed slit.

A tire includes a tread portion that includes a first circumferential groove and a first land portion. A groove bottom portion of the first circumferential groove includes a groove bottom reference surface and a plurality of projections projecting outwardly in a tire radial direction from the groove bottom reference surface. The first land portion has at least one first lateral groove extending from the first circumferential groove and terminating within the first land portion. In a tread plan view, an entirety of a first lateral groove extension region obtained by extending a connection portion of the first lateral groove at the first circumferential groove to the groove bottom portion of the first circumferential groove so as to be parallel to a tire axial direction is formed on the groove bottom reference surface.