A pneumatic tire includes a sipe line that is a line constituted of continuation of the sipe. The sipe line extends from one grounding end toward the other grounding end of the tread portion and has an amplitude in both a tire circumferential direction and a tire width direction.

A tread pattern of a pneumatic tire includes circumferential main grooves, a land portion defined by the circumferential main grooves in the lateral direction, and sipes at intervals in a circumferential direction, the sipes connecting the circumferential main grooves with each other. Each of the sipes has a peak-like shape protruding to a first side in the circumferential direction. When, in a profile cross-section of the tread portion taken along the lateral direction, an arc passing through two land portion edge points at which a tread surface of the land portion is connected with groove wall surfaces of the circumferential main grooves and having a center point positioned on the equator line is set to a standard profile line, a profile line formed by the tread surface of the land portion is a swelling profile line protruding outward of the standard profile line in a radial direction.

In a pneumatic tire, a pair of width-oriented sipes that straddle one of circumferential recessed regions are arranged in such fashion as to appear to partially mutually overlap as viewed in a tire width direction, each of the pair of width-oriented sipes comprises a sipe portion at which width is constant, and a notch portion at which width increases toward the exterior in a tire radial direction, the sipe portion is such that at least one end thereof is contiguous with at least one of the circumferential recessed regions in such fashion as to be inclined with respect to the at least one circumferential recessed region; and the notch portion is arranged at a corner at which the sipe portion intersects the at least one circumferential recessed region to form an acute angle therebetween.

A pneumatic tire includes the plurality of sipes, when, with regard to each sipe in which the shoulder-side end portion is located closest to a center side among the plurality of sipes, a position of the shoulder-side end portion of the sipe in the tire width direction is taken as a first reference position, and with regard to each sipe in which the center-side end portion is located closest to a shoulder side among the plurality of sipes, a position of the center-side end portion of the sipe in the tire width direction is taken as a second reference position, the plurality of sipes are arranged at regular intervals in the tire circumferential direction, and at other of the first reference position and the second reference position, the plurality of sipes are arranged at irregular intervals in the tire circumferential direction.

In a pneumatic tire, land portions have a plurality of sipes and at least one row of land portions in an inner side region is provided with sipes having a 3D structure. Also, the snow traction index (STI) with respect to the tire circumferential direction throughout the entire tread portion is in the range of 100STI. Also, the sipe component (STI_s_out) of the snow traction index (STI) in an outer side region and the sipe component (STI_s_in) of the snow traction index (STI) in the inner side region have the relationship of 1.1STI_s_in/STI_s_out. Also, the peripheral length ratio PLR_out of the three-dimensional structure portion in the outer side region and the peripheral length ratio PLR_in of the three-dimensional structure portion in the inner side region have the relationship of 1.1PLR_in/PLR_out.

A tyre comprises a tread portion comprising a shoulder main groove and a shoulder land region. The shoulder land region includes an outer region, a middle region, and an inner region. The shoulder land region is provided with a plurality of shoulder sipes having components in a tyre axial direction. A sipe ratio of the middle region is smaller than the sipe ratio of the outer region and the sipe ratio of the inner region.

A tyre whose position when mounted on a vehicle is specified has a tread portion in which an outer tread edge and an inner tread edge are defined. The tread portion has a first main groove, a second main groove arranged on a side of the inner tread edge of the first main groove, an outer land region defined between the outer tread edge and the first main groove, a center land region defined between the first main groove and the second main groove, and an inner land region defined between the second main groove and the inner tread edge. A width in a tyre axial direction of the outer land region is larger than a width in the tyre axial direction of each of the center land region and the inner land region. The center land region is provided with first sipes each completely crossing the center land region.

A tread pattern of a pneumatic tire includes three or more circumferential main grooves extending in a tire circumferential direction, a plurality of lug grooves provided in a land portion defined by two circumferential main grooves, and a sipe provided between adjacent lug grooves. The sipe is a composite sipe having a two-dimensional portion and a three-dimensional portion. Among open ends on both sides of the lug groove, an open end on an identical side to an end portion of the sipe at which the two-dimensional portion is provided is provided with a raised bottom portion.

A heavy truck tire directional tread is provided that has two successive asymmetrical sipes (14) in the longitudinal direction that share at least some of the same offset from a tread edge in the lateral direction. Each of the two asymmetrical sipes (14) has a body (28) and a tear drop (30). The surface of the bottom of the sipe (14) has a radius of curvature that is not the same along the entire surface of the bottom. The geometry of the sipes resists crack initiation and propagation and is governed by the equation R.sub.A.B-avg>1-4?R.sub.ref, wherein R.sub.a.B-avg is the average radius of a particular portion of the bottom of the sipe, and Rref is a reference radius of the bottom of the sipe.

A tyre comprises a tread portion having a land region including a ground contacting surface defined between a first vertical edge and a second vertical edge and a lateral groove including a first portion extending from the first vertical edge, a second portion extending from the second vertical edge, and a connection portion connecting therebetween. The connection portion is a portion between a first small edge protruding circumferentially from the first portion and a second small edge protruding toward a circumferentially opposite side to the first small edge. A length in the tyre circumferential direction of each of the first and second small edges is smaller than a maximum groove width of each of the first and second portions. At least a part of the connection portion has a raised bottom portion having a depth smaller than that of the lateral groove at the first and second vertical edges.