A pneumatic tire comprises in a tread surface thereof a land portion that comprises a plurality of blocks. Each of the blocks comprises in a contact patch thereof a plurality of narrow shallow grooves and a plurality of recessed portions disposed separated from the narrow shallow grooves. The narrow shallow grooves have a groove width of from 0.2 mm to 0.7 mm and a groove depth of from 0.2 mm to 0.7 mm. The recessed portions have the same depth as the narrow shallow grooves.

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.

Devices with internal flexibility sipes, such as slits, provide improved flexibility, improved cushioning to absorb shock and/or shear forces, and improved stability of support. Siped devices can be used in any existing product that provides or utilizes cushioning and stability. These products include human and other footwear, both soles and uppers, as well as orthotics; athletic, occupational and medical equipment and apparel; padding or cushioning, such as for equipment or tool handles, as well as furniture; balls; tires; and any other structural or support elements in a mechanical, architectural, or any other product.

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 22 includes a plurality of ribs 68 aligned in an axial direction. A rib 68s, among the plurality of ribs 68, disposed on an outer side in the axial direction is sectioned into a body portion 74 and a side portion 76 by a groove 72 that extends in a circumferential direction. The tire 22 includes a tread 26 and a pair of sidewalls 28. The sidewalls 28 extend almost inward from ends, respectively, of the tread 26 in a radial direction. The tread 26 includes a base layer 52, and a cap layer 54 disposed outward of the base layer 52 in the radial direction. The side portion 76 is formed by the cap layer 54 and a corresponding one of the sidewalls 28. The sidewall 28 is stacked on the cap layer 54 in the side portion 76.

A method of making a tire tread includes mixing a tire tread compound including a virgin rubber component and a reclaimed rubber component, forming a green sheet from the tire tread compound, and curing the green sheet to form a cured tire tread. The reclaimed rubber component may have a Mooney viscosity (ML (1+4) @ 100° C.) of greater than 65. The reclaimed rubber component may also have a crosslink density that is between 20 and 50% of the crosslink density of the reclaimed rubber prior to reclaiming.

A method of making a tire tread includes mixing a tire tread compound including a virgin rubber component and a reclaimed rubber component, forming a green sheet from the tire tread compound, and curing the green sheet to form a cured tire tread. The reclaimed rubber component may have a Mooney viscosity (ML (1+4) @ 100° C.) of greater than 65. The reclaimed rubber component may also have a crosslink density that is between 20 and 50% of the crosslink density of the reclaimed rubber prior to reclaiming.

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.