Provided is a pneumatic tire in which a plurality of ribs which extend in a tire circumferential direction are formed in a tread portion by a plurality of main grooves which extend in the tire circumferential direction, wherein, in a center rib of the plurality of ribs, the center rib being divided at a center portion in a tire width direction, a plurality of closing slits which each extend in the tire width direction from one end portion communicating with the main groove, and terminate at another end portion in the center rib is formed, and wherein the plurality of closing slits are formed so as to be opposed to each other on both sides of the center rib in the tire width direction.

The interval along the tire circumferential direction between sipes adjacent in the tire circumferential direction is 2 to 10 times the depth of the sipes. In the depth direction of the sipes, the sipes each have at least three sipe portions divided by at least two bent portions, and a bent portion angle formed between adjacent sipe portions with one of the bent portions therebetween is greater at the tread surface side than at the sipe bottom side.

Provided is a 5-rib tire that can have improved steering stability and noise performance A tread portion 2 includes four circumferential grooves 3 and five land portions 4. Two tread ends are ends of a 50%-load ground-contact surface. Each of the five land portions 4 is provided with no groove having a groove width greater than 2.0 mm, and is provided with only sipes 9. The five land portions 4 include a shoulder land portion 11. The shoulder land portion 11 is provided with a plurality of shoulder sipes 20. At least one of the shoulder sipes 20 includes an inclined portion 21 and an axial portion 22. The axial portion 22 cross the tread end.

The pneumatic tire for passenger vehicles according to the present disclosure comprises a carcass consisting of plies of radially arranged cords, spanning toroidally between a pair of bead portions; the cross-sectional width SW and the outer diameter OD of the tire satisfy a given relationship; the land portion has a plurality of width direction sipes extending in the tire width direction; the pitch length in the tire circumferential direction of the plurality of width direction sipes is 3 mm to 10 mm; and the width direction sipe has a widened portion on the sipe bottom side where the sipe width is larger than that on the tread surface side.

In a pneumatic tire, a block includes recess/protrusions on a road contact surface. Additionally, a recess/protrusion height of the recess/protrusions is from 0.1 mm to 1.0 mm. A width of the recess/protrusions is from 0.1 mm to 0.8 mm. A recess/protrusion region is where an arrangement interval between adjacent recess/protrusions is not greater than 1.2 mm. A smooth region other than the recess/protrusion region has an arithmetic mean roughness of the road contact surface of the block not greater than 50 m. A lateral length of the road contact surface of the block in a tire lateral direction is defined. In this case, the block includes the recess/protrusion region and the smooth region in an optional cross-section in a lateral range of not less than 40% of a lateral length of the road contact surface of the block.

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 first tread for a tire includes a first circumferential groove axially separating a circumferential first rib and a second circumferential rib, a first outer surface of the first rib having at least one circumferential column of circumferential, double blind perforations extending linearly fully around the first outer surface of the first rib.

A tread portion of a pneumatic tire is divided into a center region at a center portion in a tire width direction and shoulder regions disposed on both sides of the center region. Each of the center region includes ribs which are formed by a plurality of main grooves extending in a tire circumferential direction. The shoulder region includes: a plurality of inclined grooves which are inclined toward the outside in a tire width direction and toward a direction opposite to a tire rotational direction at the time of advancing a vehicle; and a shoulder block surrounded by the inclined grooves.

The present invention provides a pneumatic tire and a rubber composition for tires, which have improved durability at high temperatures and during high-speed running while ensuring good ice performance. The present invention relates to a pneumatic tire, including a tread, the tread including blocks having an average ripe density of 1.0 cm/cm.sup.2 or higher and an average height of 0.6 to 2.0 cm, the blocks containing a rubber composition having a tan at 100 C. of 0.179 or less as determined at an initial strain of 10%, a dynamic strain of 2%, and a frequency of 10 Hz, and has a ratio of the modulus at 100 C. to the modulus at room temperature of 69% or greater as determined in accordance with JIS K6251:2010.

A pneumatic tire including a center block row 21 provided in a center area of a tread surface 1, wherein the center block row includes a plurality of center blocks 210 arranged along a tire circumferential direction, the plurality of center blocks includes a plurality of first center blocks 211 and a plurality of second center blocks 212, the plurality of first center blocks and the plurality of second center blocks have polygonal shapes on the tread surface, the polygonal shape formed by each second center block has a same number of sides as, but a different shape than, the polygonal shape formed by each first center block, each first center block and each second center block has one or more sipes, and a number n of sipes included in each second center block is greater than a number m of sipes included in each first center block.