A tread surface 20 of the tire 2 includes a center portion C and a pair of shoulder portions S. A contour line of the tread surface 20 is divided into ten parts. Among the ten parts, two parts including an equator PC are represented by arcs, and two parts including ends PE of the tread surface 20, respectively, are represented by arcs. A bank angle θb is larger than a camber angle θc. A ratio of a degree of curvature Bs of the shoulder portion S to a width TW of the tread surface 20 is not less than 50%. A ratio of a camber height d to a tire cross-sectional height H is not less than 50%.

In a tire meridian cross-section in a 5% internal pressure state of a heavy duty tire, a first radius of curvature of a first ground-contact surface profile of each of a center land portion, an inner region of a first middle block, an outer region of the first middle block, and a first shoulder block can be defined. In addition, a ratio (Wa/Da) of a groove width Wa to a groove depth Da of a center circumferential groove may not be larger than 0.25. Furthermore, a ratio (Lb/La) of a maximum length Lb in a tire axial direction to a maximum length La in a tire circumferential direction in the first middle block can be defined.

Provided is a tire including a tread portion. The tread portion includes two circumferential grooves and three land portions. The three land portions include a crown land portion disposed on a tire equator, and two shoulder land portions including tread contact ends. At least one of the shoulder land portions includes a plurality of main inclined grooves and a plurality of subsidiary inclined grooves. The main inclined grooves have tire-axially inner ends ending in the shoulder land portions and tire-axially outer ends disposed outwardly of the tread contact ends Te in the tire axial direction. The subsidiary inclined grooves have tire-axially inner ends ending in the shoulder land portions and tire-axially outer ends ending in the shoulder land portions.

A tire having a central axis and a radius further includes a circumferential tread having a convex cross-section. The convex cross-section is defined by a radius that is less than a maximum radius of the tire. A pair of sidewalls extends from opposite sides of the circumferential tread. Each of the pair of sidewalls has a concave cross-section that is defined by a radius that is greater than a maximum radius of the convex cross-section of the circumferential tread.

In a tire, a tread includes a cap layer forming a part of an outer surface of the tire, a base layer disposed inwardly of the cap layer in a radial direction, and an intermediate layer disposed between the cap layer and the base layer in the radial direction. A loss tangent of the intermediate layer at 30° C. is less than a loss tangent of the cap layer at 30° C. and a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. The tread includes at least two three-layer body portions formed of the cap layer, the intermediate layer, and the base layer, and at least one two-layer body portion that is formed of the cap layer and the base layer and disposed between a first three-layer body portion and a second three-layer body portion.

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 includes a tread part formed such that the tread part includes a crown profile including tire equator, and a pair of shoulder profiles extending from outer sides of the crown profile to tread edges. In a tire cross section including tire rotation axis in 5% internal pressure state in which the tire is mounted to a normal rim, filled with air at internal pressure of 5% of normal internal pressure and loaded with no load, each of the crown and shoulder profiles has an arc shape convex toward tire radial direction outer side such that ratio Rc/Rs of curvature radius Re of the crown profile to curvature radius Rs of each shoulder profile is 7.0 or more, and a tire axial direction distance from the equator to a connecting point between the crown profile and each shoulder profile is 0.70 or more times a tread half width.

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.

In a tire, a tread includes a cap layer forming a part of the outer surface of the tire, an intermediate layer disposed inwardly of the cap layer in the radial direction, and a base layer disposed inwardly of the intermediate layer in the radial direction. A loss tangent of the intermediate layer at 30° C. is less than a loss tangent of the cap layer at 30° C., and a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. An outer end of the cap layer is disposed outwardly of an outer end of the base layer in the axial direction. In the radial direction, a position of the outer end of the cap layer coincides with a position of the outer end of the base layer, or the outer end of the cap layer is disposed inwardly of the outer end of the base layer.