A tire comprises a tread portion having an outboard tread edge To and an inboard tread edge Ti. The tread portion is provided with: an outboard shoulder main groove extending continuously in the tire circumferential direction; an outboard crown main groove extending continuously in the tire circumferential direction and disposed between the outboard shoulder main groove and a tire equator; and outboard lateral grooves extending from the outboard crown main groove to the outboard tread edge To. The groove width of each of the outboard lateral grooves is decreased toward the outboard crown main groove 4.

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.

Provided is a pneumatic tire having plurality of compound grooves, each including a lateral groove having a first end that communicates with a main groove on one side thereof and a second end that terminates inside a land portion, and further including a sipe that extends from the second end of the lateral groove to the main groove on the other side thereof, are formed at an interval in a tire circumferential direction in at least one row of the land portions positioned inside a center region. The compound grooves are disposed so that an opening direction of the lateral grooves relative to the main grooves alternatingly reverses in the tire circumferential direction. The lateral grooves each include a broad width portion and a narrow width portion.

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.

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.

The tread has four grooves that delimit a central, intermediate and edge regions. Each intermediate region is divided into elongated raised elements that delimit oblique grooves which open into the circumferential grooves and are inclined at an average angle of between 30 and 60 degrees relative to the circumferential direction. The raised elements have an average circumferential length of between 50 and 70 mm. The depth of the oblique grooves is at least 30% of the depth of the circumferential grooves. Each raised element has a plurality of sipes that open into the oblique grooves. Each raised element also has an internal and oblique cut that has a total depth at least equal to 75% of the thickness PMU to be worn away. The oblique cut has a wide part and a part that forms a sipe that extends by a channel that forms a new groove after wear.

A tire includes a plurality of circumferential main grooves extending in a tire circumferential direction, and a pair of shoulder land portions and one or more rows of center land portions defined by the plurality of circumferential main grooves. Further, at least one of the pair of shoulder land portions includes a plurality of shoulder lug grooves and a plurality of shoulder blocks defined and formed by the plurality of shoulder lug grooves. Additionally, at least a part of the plurality of shoulder blocks includes a notch portion that connects edge portions separated from a tire ground contact edge and a buttress portion. Additionally, the notch portion has a step-shaped wall surface in a cross-sectional view in a tire meridian direction.

A pneumatic tire has inner mediate land portions and center land portion(s) that are divided into a plurality of blocks by lateral grooves. Each of the lateral grooves includes a pair of wide portions opening to a main groove and a narrow portion coupling the pair of the wide portions. one-side-closed sipes are formed in a bottom of each of the lateral grooves formed in the inner mediate land portions. The one-side-closed sipes are open at the wide portions and close at the narrow portion. a both-sides-open sipe is formed in a bottom of each of the lateral grooves formed in the center land portion or portions. The both-sides-open sipe is open at the wide portions and at the narrow portion.

A tire 1 comprises a tread portion 2 provided with an outer shoulder main groove 3 in a part closest to an outside tread edge (To) and an outer crown main groove 4 on a side of an inside tread edge (Ti) of the outer shoulder main groove 3 both extending continuously in the tire circumferential direction, and outer transverse grooves 9 connecting between the outside tread edge (To) and the outer crown main groove 4 so that an outer shoulder land region 7A is defined between the outside tread edge (To) and the outer shoulder main groove 3 and an outer middle land region 7B is defined between the outer shoulder main groove 3 and the outer crown main groove 4. A maximum axial width Ws of the outer shoulder land region 7A is larger than a maximum axial width Wm of the outer middle land region 7B.

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.