A heavy duty tire has a carcass extending from a tread portion to a bead core in a bead portion through a sidewall portion, and a belt layer disposed on the outside of the carcass in the tire radial direction and on the inside of the tread portion. In a state in which a distance between a pair of bead heels is kept at 110% of a wheel rim width of a standard wheel rim and no inner pressure is applied, the contour shape of the tread portion is formed by a 1st circular arc having a center on the tire equatorial plane, and a pair of 2nd circular arcs, disposed on both outsides of the 1st circular arc in the tire axial direction. The radius of the 2nd circular arc is more than the radius R1 of the 1st circular arc. One 2nd circular arc has the center on the other 2nd circular arc side of the tire equator in the tire axial direction, and the other 2nd circular arc has the center on the one 2nd circular arc side of the tire equator in the tire axial direction.

A heavy duty tire is disclosed. The distance from the radially outer surface of a belt layer to the tire's inner surface is 15 to 23 mm when measured along a tire radial direction line passing through the bottom of a shoulder main groove. The width of the shoulder main groove is more than the width of a center main groove. The ratio Wc:Wm:Ws of the average width Wc of a center land portion, the average width Wm of a middle land portion, and the average width Ws of a shoulder land portion is 1.00:1.00 to 1.08:1.03 to 1.13. The middle land portion is provided with a plurality of middle axial grooves. The shoulder land portion is provided with a plurality of shoulder axial grooves. The width of the shoulder axial groove is more than the width of the middle axial groove. The angle θs of the shoulder axial groove is more than the angle θm of the middle axial groove with respect to the tire axial direction.

A heavy duty tire is disclosed. The distance from the radially outer surface of a belt layer to the tire's inner surface is 15 to 23 mm when measured along a tire radial direction line passing through the bottom of a shoulder main groove. The width of the shoulder main groove is more than the width of a center main groove. The ratio Wc:Wm:Ws of the average width Wc of a center land portion, the average width Wm of a middle land portion, and the average width Ws of a shoulder land portion is 1.00:1.00 to 1.08:1.03 to 1.13. The middle land portion is provided with a plurality of middle axial grooves. The shoulder land portion is provided with a plurality of shoulder axial grooves. The width of the shoulder axial groove is more than the width of the middle axial groove. The angle θs of the shoulder axial groove is more than the angle θm of the middle axial groove with respect to the tire axial direction.

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.

The pneumatic tire of this disclosure includes on a tread surface four or five circumferential grooves, and includes a pair of shoulder land portions, a pair of intermediate land portions, and one or a pair of central land portions partitioned thereon, wherein: in a tread widthwise cross sectional view at an unloaded condition when the tire is mounted to an applicable rim and applied with a prescribed internal pressure, when drawing a virtual arc R1 protruding to a tire radial outer side, of which a center of curvature is located on a tire equatorial plain, across four tread widthwise edges adjacent to the circumferential grooves of outlines of the pair of intermediate land portions, a correlation among each protrusion amount t1, t2 and t3 of outlines of the central land portions, the intermediate land portions and the shoulder land portions from the virtual arc R1 satisfies:

t1<t2, and t3<t2.

The pneumatic tire of this disclosure includes on a tread surface four or five circumferential grooves, and includes a pair of shoulder land portions, a pair of intermediate land portions, and one or a pair of central land portions partitioned thereon, wherein: in a tread widthwise cross sectional view at an unloaded condition when the tire is mounted to an applicable rim and applied with a prescribed internal pressure, when drawing a virtual arc R1 protruding to a tire radial outer side, of which a center of curvature is located on a tire equatorial plain, across four tread widthwise edges adjacent to the circumferential grooves of outlines of the pair of intermediate land portions, a correlation among each protrusion amount t1, t2 and t3 of outlines of the central land portions, the intermediate land portions and the shoulder land portions from the virtual arc R1 satisfies:

t1<t2, and t3<t2.

The pneumatic tire of this disclosure comprises on a tread surface one or more land portions, wherein the land portions is formed into a protruding shape such that its tire radial outline in a tire widthwise cross section protrudes to a tire radial outer side, the outline includes, in the tire widthwise cross section, at least a first arcuate surface having a radius of curvature of a tire widthwise center of the land portion, and second arcuate surfaces having radiuses of curvature smaller than the first arcuate surface and located on both tire widthwise edges of the land portion, sipes extending in the tire width direction are formed on the land portions formed into the protruding shape, the sipes have chamfer portions, and the chamfer portions have chamfer widths on at least one of both tire widthwise edges larger than chamfer widths on the tire widthwise center.

The pneumatic tire of this disclosure comprises on a tread surface one or more land portions, wherein the land portions is formed into a protruding shape such that its tire radial outline in a tire widthwise cross section protrudes to a tire radial outer side, the outline includes, in the tire widthwise cross section, at least a first arcuate surface having a radius of curvature of a tire widthwise center of the land portion, and second arcuate surfaces having radiuses of curvature smaller than the first arcuate surface and located on both tire widthwise edges of the land portion, sipes extending in the tire width direction are formed on the land portions formed into the protruding shape, the sipes have chamfer portions, and the chamfer portions have chamfer widths on at least one of both tire widthwise edges larger than chamfer widths on the tire widthwise center.

A pneumatic tire has a high wet performance with keeping steering stability and wear resistance. Each of the middle land portions (12) is provided with middle sipes (15) and a middle sub-groove (16). Each of the middle sipes (15) has an arc-like shape such that an angle (θ1) with respect to the circumferential direction of the tire gradually increases from its inner end (15i) towards its outer end (15o). A circumferential length (L2) is in a range of from 0.6 to 1.0 times the arrangement pitch (P2) of the middle sipe (15). The middle sub-groove (16) communicates with a shoulder main groove (10), terminates without communicating with a crown main groove (9), and has an arc-like shape having an angle (θ2) that gradually increases from its inner end (16i) to its outer end (16o). A length (L3) of the middle sub-groove (16) is less than the length (L2) of the middle sipe, and the adjacent middle sipe (15) and middle sub-groove (16) overlap one another in the axial direction of the tire.

A pneumatic tire has a high wet performance with keeping steering stability and wear resistance. Each of the middle land portions (12) is provided with middle sipes (15) and a middle sub-groove (16). Each of the middle sipes (15) has an arc-like shape such that an angle (θ1) with respect to the circumferential direction of the tire gradually increases from its inner end (15i) towards its outer end (15o). A circumferential length (L2) is in a range of from 0.6 to 1.0 times the arrangement pitch (P2) of the middle sipe (15). The middle sub-groove (16) communicates with a shoulder main groove (10), terminates without communicating with a crown main groove (9), and has an arc-like shape having an angle (θ2) that gradually increases from its inner end (16i) to its outer end (16o). A length (L3) of the middle sub-groove (16) is less than the length (L2) of the middle sipe, and the adjacent middle sipe (15) and middle sub-groove (16) overlap one another in the axial direction of the tire.