A tire 2 includes a tread 4 and a belt 14 including inner and outer layers 38 and 40. Each end of the outer layer 40 is located axially inward of an end of the inner layer 38. A circumferential narrow groove 48 is formed on each shoulder land portion 46s so as to continuously extend in a circumferential direction. A groove width of the circumferential narrow groove 48 is smaller than that of a shoulder circumferential groove 44s. The circumferential narrow groove 48 is located between the shoulder circumferential groove 44s and the end of the outer layer 40 in an axial direction. A ratio of a distance in the axial direction from the shoulder circumferential groove 44s to the circumferential narrow groove 48 to a distance in the axial direction from the shoulder circumferential groove 44s to the end of the outer layer 40 is 15% to 55%.

Heavy load pneumatic radial tire according to the present invention includes: tread rubber 6 having laminated structure of cap rubber 5 and base rubber 4; and four or more belt layers 3a-3e disposed radially inward of tread rubber 6. A radially outer side of a width direction side edge of at least one of radially outermost belt layer 3e and widest-width belt layer 3c is covered by reinforcing rubber layer 7 that terminates on a radially inner side of tread rubber 6 without reaching tire equatorial plane E. Relative relation between reinforcing rubber constituting reinforcing rubber layer 7 and base rubber 4 in terms of modulus of rebound elasticity satisfies the condition: reinforcing rubber<base rubber 4.

A tire tread formed from a rubber composition having a functionalized SBR and a BR that is reinforced with between 95 phr and 125 phr of a silica filler and includes a plasticizing system to adjust the glass transition temperature to be between −30° C. and −15° C. and the dynamic modulus G* at 60° C. to be between 0.9 MPa and 1.15 MPa. The tread includes central tread blocks having an average central tread block length of between 6.5 mm and 10 mm and shoulder tread blocks having an average shoulder tread block length of between 10 mm and 20 mm. Furthermore the tread is limited to being between 6.5 mm and 7.7 mm thick. In particular embodiments the rubber composition may be just the functionalized SBR.

A tire (10) for a passenger vehicle comprises a tread comprising at least one regulation wear indicator (46) defining a regulation wear threshold, a tread layer (52) comprising an elastomeric tread material exhibiting a complex dynamic shear modulus G*_1 and a dynamic loss tanD0_1, and a backing layer (54) for the tread layer (52) that comprises an elastomeric backing material exhibiting a complex dynamic shear modulus G*_2 and a dynamic loss tanD0_2 such that tanD0_2≥0.37×tanD0_1 and G*2≥0.90×G*1.

Provided is a pneumatic radial tire for a passenger car that exhibits both riding comfort at low temperatures and stealing stability at high-speed running. The present invention is a pneumatic radial tire for a passenger car, in which: a carcass and a tread are provided; the tread is integrated into a standardized rim; when internal pressure is at a standardized internal pressure, the tire has a cross-sectional width Wt (mm) and an outer diameter Dt (mm) satisfying 1963.4≤(Dt.sup.2π/4)/Wt≤2827.4; the tread comprises at least one main groove in a running surface of the tread, extending in the circumferential direction of the tread; the land/sea ratio at the tread running surface is greater than 55% and less than 85%; and a rubber composition that forms the tread has a loss tangent (tan δ) which, when measured at a frequency of 10 Hz, an initial strain of 2%, and a dynamic strain rate of 1%, is such that |20° C. tan δ-50° C. tan δ| is at least 0.01 and less than 0.15, and 15° C. tan δ-20° C. tan δ| is greater than 0.15 and less than 0.70.

A tire composition is disclosed. The composition comprises a rubber component and based on 100 parts by weight (phr) of the rubber component, 50-200 phr of covered silica, with the covered silica comprising silica core and a first resin covering the silica core, wherein the first resin is not chemically bonded to the silica core. The silica core is covered with the first resin by mixing a slurry comprising silica core with a mixture containing the first resin as a solution, an aqueous dispersion; or a solution by dissolving the first resin in a solvent.

In a tire, a shape index of a reference ground contact surface is not less than 1.20 and not greater than 1.50. In the tire, a tread includes a cap layer, an intermediate layer formed such that 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 base layer formed such that a loss tangent of the base layer at 30° C. is less than the loss tangent of the intermediate layer at 30° C. In the radial direction, the intermediate layer is disposed outwardly of the base layer and the cap layer is disposed outwardly of the intermediate layer. In a shoulder land portion of the tread, a thickness of the cap layer at a center of an axial width is less than a thickness of the cap layer on the shoulder circumferential groove side.

A tire includes a block 30. The block 30 includes a land 36b, a transverse groove 48b, a longitudinal groove 50b, and a side surface 38b. The land 36b is flat. The transverse groove 48b is recessed from the land 36b. The transverse groove 48b has inner and outer ends 52 and 54 in an axial direction of the tire. The inner end 52 of the transverse groove 48b is open on the side surface 38b. The outer end 54 of the transverse groove 48b is not open on the side surface 38b. The transverse groove 48b is localized in the inner region of the block 30 in the axial direction.

Provided is a tire comprising a tread part, the tread part comprising at least one rubber layer of a rubber composition comprising a rubber component and a thermoplastic elastomer, wherein a ratio (W.sub.T/W.sub.L) of a tire weight W.sub.T (kg) to a maximum load capacity W.sub.L (kg) of the tire is 0.0180 or less, wherein, in a dynamic viscoelasticity test (temperature-dependent measurement at 10 Hz) in accordance with JIS K 6394, the thermoplastic elastomer exhibits a tan δ peak value in a range of −20° C. to 20° C., and the peak value is 1.00 or more. While being lightweight, the tire can improve in ride comfort and particularly suppress deterioration of ride comfort due to abrasion.

An object of the present invention is to provide a tire having improved overall performance of grip performance during straight running and grip performance during cornering under a high-speed running condition.

As a result of intensive studies, it has been found that the above-described problem can be solved by, in a tire having a tread part in which a mounting direction to a vehicle is designated, dividing the tread part in a tire width direction and setting respective width and respective average values of a loss tangent tan δ of an inner tread rubber layer forming an end side inside the to vehicle when the tire is mounted to the vehicle and an outer tread rubber layer forming an end side outside the vehicle when the tire is mounted to the vehicle within predetermined ranges.