In a tire with a tread that includes tread pattern elements, a circumferential reinforcement, and first and second circumferential grooves, the circumferential reinforcement is formed of a rubber mixture having a stiffness greater than a stiffness of a rubber mixture forming a remainder of the tread. The tire has an outer side on one side of a median plane of the tire, and an inner side on an opposite side of the median plane. The first circumferential groove is disposed axially toward the outer side relative to the second circumferential groove. The circumferential reinforcement includes a reinforcing element having a tapered shape positioned in each of a group of the tread pattern elements disposed axially toward the outer side relative to one of the first and second circumferential grooves, with the reinforcing elements being axially close to an outer-side face of that circumferential groove.

A tire having a carcass reinforcement surmounted radially by a crown reinforcement having at least two working plies, the width Lt of which is equal to the width of the axially narrowest working ply, and surmounted radially by a tread (or cap) and interposed radially between the cap and the crown reinforcement by a sublayer (or base), this base extending axially and radially under all of the cap and radially on the outside of the crown reinforcement over a total width at least equal to the width Lt of the crown reinforcement, an equatorial plane dividing the cap axially into an outer half cap (TE) and an inner half cap (TI) of the same axial width, the outer half cap (TE) positioned axially towards the outside of a vehicle and the inner half cap (TI) positioned axially towards the inside of the vehicle, the base comprising an additional volume radially under the inner half cap (TI), such that the volume occupied by the base radially under the inner half cap (TI) is greater than the volume occupied by the base radially under the outer half cap (TE), and the material of the base is a rubber-based composition having hysteresis lower than the hysteresis of the rubber-based material of the cap.

A tire of which the tread contains at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in the central part than at the axially outer parts. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a part extending at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, the first blended elastomeric compound having a Z-value higher than 55 and a tan()max value lower than 0.120, the second blended elastomeric compound having a Z-value higher than 50 and a tan()max value lower than 0.100, and the complex modulus G*1% at 100 C. of the second blended elastomeric compound having a value at least 5% higher than that of the modulus G*1% at 100 C. of the first blended elastomeric compound.

A tire with a radial carcass reinforcement, having a crown reinforcement, itself capped radially by a tread connected to two beads by two sidewalls, the tread having at least two layers of blended elastomeric compounds that are radially superposed and have a voids ratio that is lower in the central part than at the axially outer parts. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a part extending at least into the region of the equatorial plane and of at least two axially outer parts formed of a second blended elastomeric compound, the first blended elastomeric compound having a macro dispersion Z-value higher than 65 and a maximum tan() value, denoted tan()max, lower than 0.150, and the second blended elastomeric compound having a maximum tan() value, denoted tan()max, lower than 0.130.

A tire of which the tread contains at least two layers of blended elastomeric compounds that are radially superposed and has a voids ratio that is lower in the central part than at the axially outer parts thereof. A first layer of blended elastomeric compounds of the tread is made up of a first blended elastomeric compound forming a central part, and of two outer parts formed of a second blended compound, the first blended compound having a Z-value higher than 55, the first blended compound and the second blended compound having a tan()max value lower than 0.110, the modulus G* of the second blended elastomeric compound having a value at least 10% higher than that of the modulus G* of the first blended elastomeric compound, a second layer of the tread, radially the outermost, being made up of a third blended compound of which the modulus G* has a value at least 10% higher than that of the modulus G* of the first blended elastomeric compound and the elongation at break of the third blended compound having a value at least 10% higher than those of the elongations at break of the first and second blended compounds.

The present invention is directed to a tire comprising a tread comprising: a plurality of circumferential grooves separating circumferential ribs, each groove comprising a bottom and two sidewalls; one or more groove reinforcements, each groove reinforcement laterally spaced from any other of said one or more groove reinforcements; wherein each groove reinforcement is arranged adjacent one circumferential groove; wherein at least one circumferential groove has no groove reinforcement adjacent to it; and wherein each groove reinforcement extends from the radially inner surface of the tread in a radially outward direction at least to the bottom of the adjacent circumferential groove to form at least part of the bottom of that groove.

A run-flat tire includes a reinforcing rubber layer with a roughly crescent-shaped meridian cross-section disposed in sidewall portions at both sides in a tire width direction. The tread portion is provided formed of a tread rubber that includes a cap tread rubber and an undertread rubber disposed on an inner side of the cap tread rubber in a tire radial direction and having a higher hardness than the cap tread rubber. In a meridian cross-section, a gauge of the undertread rubber on a shoulder land portion on an outer side of an outermost main groove located furthest outward in the tire width direction is thicker than a gauge of the undertread rubber of a center land portion closest to a tire equatorial plane.

A tire the tread of which contains at least three circumferential grooves, having at least three radially superposed layers of elastomeric compounds.

A first elastomeric compound constituting the first layer forming the radially outer part of the tread has a maximum value of tan()max, greater than 0.110, a second elastomeric compound constituting the second layer radially on the inside has a tan()max at least 10% lower than the first elastomeric compound, the radially innermost third layer of the tread consists of at least two first parts and of at least three second parts axially, each one in contact with at least one of the at least two first parts, the at least two first parts axially centered on a radial plane passing through one of the at least three circumferential grooves consisting of the second compound and the at least three second parts consisting of a third elastomeric compound having a maximum value of tan(), denoted tan()max, at least 10% lower than the second elastomeric compound.

A non-regroovable tire for a heavy-duty vehicle, with an increased service life. The median portion (23) of the tread (2) has at least one cut (22), the latter has a wide radially inner first portion (221) having a height (H1) at least equal to 0.2 times the depth (H) of the cut (22) and a mean width (W1) greater than 2 mm, and a narrow second portion (222) having a height (H2) at least equal to 4 mm and at most equal to the difference between the depth (H) of the cut (22) and the depth (H1) of the wide first portion (221), and a mean width (W2) at most equal to 2 mm, and the minimum thickness (Ei) of the intermediate layer (3), measured between the bottom (220) of the cut and the crown reinforcement (4), is at least equal to 2 mm and at most equal to 4 mm, and satisfies the relationship: Ei.sup.3/W112 mm.sup.2, Ei and W1 being expressed in mm.