A tire has a tread portion comprising: a crown land zone provided with a crown auxiliary groove and crown lateral grooves; and a shoulder land zone provided with a shoulder auxiliary groove and shoulder lateral grooves. The axial width of the shoulder land zone is larger than the axial width of the crown land zone. The groove widths of the crown auxiliary groove and the shoulder auxiliary groove are smaller than that of a shoulder main groove. The lateral crown groove comprises a radially outer wide portion and a radially inner narrow sipe-like portion.

A tire, the speed rating of which is at least V, comprises a tread, having a volumetric void ratio at least equal to 2% and at most equal to 20%, having a central part Pc comprising at least one groove, and two lateral parts PI each having a volumetric void ratio at most equal to 2%. The central part Pc of the tread has an axial width at most equal to one third of the axial width LBDR of the tread, and any portion of the central part Pc of the tread that is circumferentially delimited by two meridian planes separated by a circumferential distance dc equal to one tenth of the outer perimeter P of the tire comprises at least one and at most three grooves that open onto the meridian planes delimiting the portion in question.

The tire (10) for a passenger vehicle has an axially central portion and axially lateral portions. The axially central portion and each axially lateral portion satisfies just one of conditions I, II, III: I—the portion comprises no transverse cut (90, 90′), II—the portion comprises N transverse cuts (90, 90′) arranged in such a way that π×OD/N≥40 mm, III—the portion comprises N transverse cuts (90, 90′) arranged in such a way that π×OD/N≤24 mm, condition I or II being satisfied by the axially central portion or by an axially lateral portion, and condition III being satisfied by the axially central portion or by an axially lateral portion.

Tread (1) for a heavy-duty vehicle tire having a total thickness corresponding to the thickness of material to be worn away during running, this tread having, in the new state, a tread surface (10) intended to come into contact with a roadway when running. The tread comprises at least one hidden cavity (2) forming a new groove opening onto the tread surface after a predetermined amount of partial wear. Cavity (2) comprises two opposite lateral walls (21, 22) connected together by bottom (23) radially towards the inside and by crown part (24) radially towards the outside. Crown part (24) is provided with a plurality of fine grooves (25) extending radially towards the outside from crown part (24) delimiting the cavity and extending in a direction that makes an angle at least equal to 40 degrees with the main direction of cavity (2).

A tread pattern of a heavy duty pneumatic tire includes: a linear shaped center lug groove; a pair of circumferential main grooves formed in a wave shape in a tire circumferential direction; a center block; and a central narrow groove that does not have a linear shape, having an opening end that opens in the adjacent center lug grooves in a tire lateral direction position excluding on a tire equator line, and having a groove width that is narrower than the groove width of the shoulder lug groove. The groove width of the center lug groove and the circumferential main groove is narrower than the groove width of the shoulder lug groove. The central narrow groove has a portion that extends outwards in a tire lateral direction from the opening end in the half tread region where the opening end is positioned.

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 δ 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 includes a lateral groove that includes a groove bottom surface extending in a direction crossing a tire circumferential direction, and a protrusion provided on the groove bottom surface and extending in an extension direction of the groove bottom surface. The protrusion includes a main body, and an end portion provided on at least one side in a longitudinal direction of the main body and shaped such that a height of the protrusion from the groove bottom surface decreases from an inside to an outside in the longitudinal direction of the main body. The end portion includes an upper surface that forms a circular arc recessed inward in a tire radial direction in a cross section crossing a width direction of the protrusion.

In a pneumatic tire including a tread portion, a sidewall portion, a bead portion, a carcass layer mounted between a pair of bead portions, a plurality of main grooves extending in the tire circumferential direction and formed in the tread portion, and a plurality of land portions defined by the main grooves, the carcass layer includes a carcass cord formed of a polyester fiber cord, an elongation at break of the carcass cord is from 20% to 30%, and a groove area ratio SgA in a ground contact region of the tread portion is from 20% to 40%, a groove area ratio SgB in a center region of the tread portion satisfies a relationship 1.1≤SgB/SgA≤1.5, and a depth of the main groove included in the center region is from 5 mm to 8 mm.

A tire including, in a tread surface (12), a plurality of shoulder main grooves extending in a tire circumferential direction, a plurality of lug grooves (351) extending in a direction intersecting the shoulder main groove, and a plurality of blocks B defined by the shoulder main grooves and the lug grooves (351). The tread surface (12) of the block B includes circumferential narrow grooves (352) each extending in the tire circumferential direction and a plurality of sipes that are provided on both sides of the circumferential narrow grooves in a tire width direction so as to be separated from the circumferential narrow grooves (352) and are disposed side by side in the tire circumferential direction and extend in the tire width direction. The circumferential narrow groove (352) includes a shallow bottom portion (3521) and a deep bottom portion (3522) having different depths from the tread surface (12). The deep bottom portion (3522) has a depth from the tread surface (12) deeper than a depth of the shallow bottom portion (3521) and is provided in a central portion of the block B in the tire circumferential direction.

Crown of a tire for a heavy vehicle that is desensitized to attacks. The tire (1) comprises tread (2) having a median degree of surface siping TL.sub.C, expressed in m/m.sup.2, equal to the ratio between the cumulative length L.sub.DC of the cuts (21), present in a median portion of tread of axial width W.sub.C, and the median area A.sub.C of the radially outer surface (23) of the tread (2), and protective reinforcement (4) comprising at least two protective layers (41, 42) that are formed of elastic metallic reinforcers and have a maximum breaking strength R.sub.max, expressed in daN/m, such that the median degree of surface siping TL.sub.C of tread (2) is at least equal to 5 m/m.sup.2 and a coupling ratio C.sub.C, equal to the ratio between the maximum breaking strength R.sub.max and the median degree of surface siping TL.sub.C, is at least equal to 18 000 daN.