A pneumatic tire includes at least four circumferential main grooves extending in a tire circumferential direction and at least five land portions defined by the at least four circumferential main grooves. A center land portion includes a plurality of center lug grooves extending through the center land portion in a tire lateral direction and disposed at predetermined intervals in the tire circumferential direction, and a plurality of center blocks that are defined by the plurality of center lug grooves. The center blocks each include a narrow shallow groove that extends through the center block in the tire lateral direction and that remains open when the tire comes into contact with the ground.

A tire includes a tread portion that includes a center main groove, an outer main groove provided on an outer side in a tire width direction of the center main groove, and a lug groove extending in a direction intersecting with both main grooves. The center main groove has a zigzag shape in which a first linear portion and a second linear portion are alternately connected. The outer main groove has a zigzag shape in which a long linear portion and a short linear portion are alternately connected. The lug groove has a groove center line intersecting with the short linear portion in the zigzag shape of the outer main groove.

In a tire, a main groove has a bend where the groove wall angle relative to the tread surface normal line changes in a meridian cross-section. In first and second blocks adjacent in a width direction with the main groove therebetween, an angle between a line extended from a ridge line formed by a bend of a first block side groove wall and a line extended from a lug groove wall defining the first block is larger than an angle between a line extended from the ridge line formed by a bend of the second block side groove wall and a line extended from a lug groove wall defining the second block, and an angle of the first block side groove wall to the tread surface normal line is smaller than an angle of the second block side groove wall to the tread surface normal line.

In a tire including a block having an edge along a main groove closer to an equatorial plane and a block having an edge along a main groove farther from the equatorial plane, the angles between an imaginary line extending a ridge line formed by a bend point of a groove wall on the edge side of the main groove and imaginary lines extending each of edges adjacent in a circumferential direction with the edge interposed therebetween are an acute angle (θa) and an obtuse angle (θb), and the angles between an imaginary line extending a ridge line formed by a bend point of a groove wall on the edge side of the main groove and imaginary lines extending each of edges adjacent in the circumferential direction with the edge interposed therebetween are an acute angle (θc) and an obtuse angle (θd), with a relationship (θd−θc)<(θb−θa).

A car tyre having a tread that extends in axial direction for a width the tread including a central portion arranged across an equatorial plane, and two lateral portions opposed with respect to the central portion. The central portion is separated from the lateral portions of the tread by two circumferential grooves. The circumferential grooves have a width greater than about 6 mm. The central portion extends in axial direction for a width less than 20% of the width of the tread and includes a plurality of first sipes. Each lateral portion has a width greater than 30% of the width of the tread, and each lateral portion includes, furthermore, a plurality of transversal grooves. The transversal grooves of a lateral portion include at least a first inclined length that extends from a zone proximal to the respective circumferential grooves, moving away from the equatorial plane. The first inclined length has an inclination α≤60° with respect to equatorial plane. Each lateral portion includes a plurality of sipes. The density of the sipes decreases moving away from the equatorial plane.

The tire has a tread portion 2 comprising a plurality of main grooves and a first land portion 11 divided by the main grooves. The first land portion 11 comprises a plurality of first blocks 15 divided by first lateral grooves 14. The first lateral groove 14 is provided with a first tie bar 19 raising from a part of the groove bottom excluding its end portions in the tire axial direction. The first block 15 is provided with a first sipe 20 inclined with respect to the tire axial direction to the same orientation over its entire length from a first longitudinal edge 26 to a second longitudinal edges 27 of the block. The first sipe 20 is composed of a first portion 21 extending from the first longitudinal edge 26, a second portion 22 extending from the second longitudinal edge 27, and a third portion 23 between the first portion 21 and the second portion 22. The angle with respect to the tire axial direction of the third portion 23 is greater than the angles with respect to the tire axial direction of the first portion 21 and the second portion 22.

Provided in a tread portion of a tire are main grooves, lug grooves intersecting the main grooves, and land portions defined by the main grooves. A specific one of the land portions includes, in a ground contact surface, sipes and narrow grooves intersecting the main grooves, the narrow grooves having a depth of 1.50 mm or less. When extending from one side toward another side in the width direction, the sipes and the narrow grooves have different directions extending in the circumferential direction in the central region and have the same direction extending in the circumferential direction in both edge regions on an outer side from the central region in the width direction. The specific one of the land portions includes at least one land portion on the outer side in the width direction.

A tire comprising: a tread portion contacting a road surface; a groove provided in the tread portion; and a plurality of projections provided at groove side walls of the groove, wherein the plurality of projections are provided at least at any position within a region of from 40 to 60% of a groove depth of the groove side walls, and wherein, as seen in a cross-section in a width direction of the groove, an apex of the projection is positioned further toward a tread surface side of the tread portion than a width direction central portion of a base of the projection.

Provided is a pneumatic tire with which any change in steering stability between low-speed running and high-speed running is sufficiently minimized, and durability is also sufficiently improved. This pneumatic tire has a belt layer radially inward of the tread portion, wherein the ratio (tan δ/E*) of the loss tangent (tan δ) to the complex elastic modulus E*(MPa) of the rubber composition constituting the belt layer, as measured under the conditions of 70° C., frequency 10 Hz, initial distortion 5%, and dynamic distortion rate 1%, is 0.002 to 0.017 (inclusive), and the (formula 1) and (formula 2) are satisfied, where Wt (mm) is the cross-sectional width of the tire, Dt (mm) is the outside diameter, and the virtual volume V (mm.sup.3) is the volume of the space occupied by the tire, when the tire is installed on a standardized rim and the internal pressure is 250 kPa.

1700≤(Dt.sup.2×π/4)/Wt≤2827.4  (formula 1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (formula 2)

A pneumatic tire is provided which has sufficiently reduced rolling resistance during high-speed running and which has excellent durability. The pneumatic tire has a bead portion, carcass and tread, wherein: a bead-reinforcing layer that reinforces the bead portion from outside of the carcass is provided outside of the carcass in the tire axis direction; and the pneumatic tire satisfies (formula 1) and (formula 2) below, where Wt (mm) is the cross-sectional width of the tire when the tire installed on a standardized rim and the internal pressure is 250 kPa, Dt (mm) is the outer diameter, and the virtual volume V (mm.sup.3) is the volume of the space occupied by the tire.

1600≤(Dt.sup.2×π/4)/Wt≤2827.4  (formula 1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (formula 2)