The present technology relates to a pneumatic tire in which the ratio of the total width SW and the outer diameter OD satisfies SW/OD0.3, and grooves are provided on the tread portion. In the ground contact region of the tread portion, when the groove area ratio in the ground contact area is GR, the ground contact width is W, the region having a width of 50% of the ground contact width W and the tire equatorial plane as center is the center region, the groove area ratio in the center region is GCR, the ground contact region on the outer side in the tire width direction of the center region is the shoulder region, and the groove area ratio in the shoulder region is GSR, the ground contact region of the tread portion is formed to satisfy 10%GR25% and GCR>GSR.

A tyre includes a tread portion including an outboard middle land portion disposed between an outboard tread edge and a tyre equator. The outboard middle land portion includes first and second longitudinal edges, outboard middle lateral grooves extending from the first longitudinal edge and having terminal ends within the outboard middle land portion, first outboard middle sipes extending from the respective terminal ends of the outboard middle lateral grooves to the second longitudinal edge, and second outboard middle sipes extending from the first longitudinal edge toward the second longitudinal edge beyond the terminal ends of the outboard middle lateral grooves and terminating within the outboard middle land portion. The outboard middle land portion is not provided with any lateral grooves that extend from the second longitudinal edge toward the first longitudinal edge to reach an axial center location of the outboard middle land portion.

A pneumatic radial tire for passenger vehicles. When the tire is fitted on a rim and having an internal pressure of 250 kPa or higher, the section width SW and the outer diameter OD of the tire satisfy a predetermined relationship. A center land row is a rib-shaped land, and has center lug grooves each opening into one of the two circumferential main grooves and terminating within the center land row. Outer land rows are rib-shaped lands, each outer land row having outer lug grooves and outer auxiliary lug grooves. The outer lug grooves each open into a ground contact end in the tire width direction and terminate within the outer land row. The outer auxiliary lug grooves open into the circumferential main groove defining the outer land row, has a groove width smaller than the groove width of the outer lug grooves, and extend in the tread width direction.

A pneumatic tire includes a center land portion, intermediate land portions, and shoulder land portions each with sipes arranged at intervals in a circumferential direction. Center land sipes have a widened portion with a wide groove width at one end. Shoulder land sipes extend from the outer side of a ground contact end in a lateral direction toward an outer main groove. The orientation of the center and shoulder land sipes with respect to the circumferential direction is opposite to the orientation of intermediate land sipes. Respective inclination angles ?.sub.CE, ?.sub.MD, ?.sub.SH of the center, intermediate and shoulder land sipes satisfy ?.sub.CE<?.sub.MD<?.sub.SH<90?, an end of the intermediate land sipe on the side of the inner main groove is between ends of the center land sipes, and at any position on the entire circumference at least one center or intermediate land sipe is present on a meridian.

A pneumatic tire includes a tread having a shoulder main groove, a center main groove formed adjacent to the shoulder main groove, a shoulder land section on tire axially outer side of the shoulder main groove, and a middle land section bordered by the shoulder and center main grooves. The shoulder land section has a shoulder lug groove and a shoulder linked sipe connecting the end of the shoulder lug groove and the shoulder main groove, the middle land section has a middle lug groove and a middle linked sipe connecting the end of the middle lug groove and the center main groove, and the shoulder lug groove, the shoulder linked sipe and the middle lug groove are formed on an inclined curve extending smoothly from the tread edge in the axially inward direction, and the middle linked sipe is inclining in direction opposite with respect to the inclined curve.

An inner end (27a) of a slit (27) provided in a shoulder rib (25) in a tire width direction is terminated within the shoulder rib (25). The shoulder rib (25) includes a slit region (30) that has the slit (27) and a rib region (31) that has not the slit (27). The shoulder rib (25) protrudes to the outside of a tire reference profile line L on a cross-section in the tire width direction and has a protrusion peak (33) in the rib region (31). A ground contact surface of the shoulder rib (25) draw, on a cross-section in the tire width direction, an arch (M) passing through a ground contact end (22), the protrusion peak (33), and a point (34) on an inner sidewall of a shoulder-side main groove (21) in the tire width direction. The arch (M) passes through a point (35) on the tire reference profile line (L) or outside the tire reference profile line (L) in a normal direction of the tire reference profile line (L) at an inner end of the shoulder rib (25) in the tire width direction.

A pneumatic tire comprises a tread portion 2 provided with two shoulder main grooves 3, a crown main grooves 4, two shoulder land zones 8, and two middle land zones 7. The shoulder land zones 8 are each provided with shoulder lateral grooves 11. The middle land zones 7 are each provided with middle narrow grooves 10. Each of the middle narrow grooves 10 comprises a sipe-like narrow portion 12 whose groove width is less than 2 mm, and a wide portion 14 whose groove width is not less than 2 mm. The wide portion 14 includes an axially outer wide portion 15 formed at the axially outer end of the middle narrow groove 10.

A tread pattern of a pneumatic tire includes two outer circumferential main grooves and two inner circumferential main grooves. Each of the two inner circumferential main grooves comprises a first groove wall and a second groove wall facing the first groove wall. The first groove walls include first oblique wall elements that extend obliquely outward in a tire width direction and second oblique wall elements that extend obliquely inward in the tire width direction and extend for a shorter length than the first oblique wall elements. The second groove walls include third oblique wall elements that extend obliquely inward in the tire width direction and fourth oblique wall elements that extend obliquely outward in the tire width direction and extend for a shorter length than the third oblique wall elements.

Performance on snowy roads is improved. Provided is a pneumatic tire, of which the mounting orientation on a vehicle is indicated. An outer middle land part is formed between a first major groove and a second major groove. The first major groove has first portions and second portions alternately formed in the tire circumferential direction, the second portions being wider than the first portions. The outer middle land part is provided with a plurality of middle inclined grooves not directly interconnected with either the first major groove or the second major groove, a plurality of outer middle lug grooves connecting the second portions of the first major groove and the middle inclined grooves, and inner middle lug grooves connecting the middle inclined grooves and the second major groove. The outer middle lug grooves are provided to different positions in the tire circumferential direction than the inner middle lug grooves.

A tread pattern on a pneumatic tire is provided in regions of two intermediate land portions and has circumferential shallow grooves extending in the tire circumferential direction. An orientation of a groove inclination inclined with respect to a first direction in the tire circumferential direction of lug grooves provided in a region of one intermediate land portion, is the same as an orientation of a groove inclination inclined with respect to a second direction opposite to of the first direction of the tire circumferential direction of lug grooves provided in a region of another intermediate land portion, and the lug grooves provided in the respective regions of the intermediate land portions are bent so that the groove inclination approaches the tire circumferential direction at positions of intersection with the circumferential shallow grooves.