A tire includes a tread portion including at least one land region extending in a tire circumferential direction. The land region is provided with a plurality of axial groove portions curved so as to protrude in one direction in the tire circumferential direction in a plan view. The axial groove portions include first axial groove portions and second axial groove portions having different degree of curvature from the first axial groove portions.

A tire comprises, in the central part of its crown, at least one undulation (51) with a radial amplitude A of the radially outermost crown layer, circumferential furrows (24) and open grooves (25), some of these grooves being radially on the outside of the undulation (51). At least 50% of these grooves (25) are said to be adapted to the undulation. An open groove adapted to the undulation which it is radially on the outside of is such that the intersection points Ps of the bottom curve Cf of said groove and of the furrows (24) are at a distance from the radially outermost point Pext of said bottom curve Cf by a radial distance d2 at least equal to one third of the radial amplitude (A/3) of the undulation (51) and such that the curve Cf increases radially from the intersection points Ps to the point Pext.

In regions, divided by the tire equator, on both sides of the tread surface of a tire, the tire includes a grip area along the entire circumference of the tread, the grip area including a plurality of recessed lines, with a shape recessed toward an inner side of the tire from the outline of the tread surface, that extend from the tread edge side in a direction inclined relative to the tire equator and are arrayed in parallel, and a plurality of sipes that extend toward the tire equator in a direction inclined relative to the tire equator, starting in the grip area and terminating before the tire equator. The negative ratio in the grip area is higher than the negative ratio closer to the tire equator than the grip area.

A tire including: at least three circumferential grooves; a first shoulder portion defined by a circumferential groove and a ground contact end on one side in a width direction; a second shoulder portion defined by a circumferential groove and a ground contact end on the other side in the width direction; a first land portion located between the circumferential groove defining the first shoulder portion and a circumferential groove adjacent to the circumferential groove defining the first shoulder portion; a second land portion located between the circumferential groove defining the second shoulder portion and the circumferential groove adjacent to the circumferential groove defining the second shoulder portion; recesses extending to the first shoulder portion and the first land portion across the circumferential groove defining the first shoulder portion; and recesses extending to the second shoulder portion and the second land portion across the circumferential groove defining the second shoulder portion.

A tire includes a tread portion including a first tread edge, a second tread edge, a crown land portion arranged between the first tread edge and the second tread edge, and a first crown circumferential groove extending continuously in a tire circumferential direction adjacent to the crown land portion on a first tread edge side. The first crown circumferential groove includes a groove bottom having a plurality of protrusions projecting in a tire radial direction. The crown land portion is not provided with drainage grooves that have an opening width exceeding 2.0 mm at a ground contact surface of the crown land portion and a depth exceeding 2.0 mm of an area where a distance between two opposite groove walls thereof exceeds 2.0 mm. The crown land portion is provided with a plurality of sipes.

A tire includes a tread portion including at least one circumferential groove extending continuously in a tire circumferential direction. The at least one circumferential groove includes a groove bottom having a plurality of protrusions projecting in a tire radial direction. Each of the plurality of protrusions has a longitudinally elongated shape with a width in a tire axial direction and a length in the tire circumferential direction that is greater than the width. Each of the plurality of protrusions includes a tapered portion whose width decreases in the tire circumferential direction.

Provided is a tire including a tread portion. The tread portion can include a first shoulder land portion. The first shoulder land portion 11 can include a shoulder lateral groove and a shoulder sipe. The shoulder lateral groove can include a minimal portion in which a groove width of the shoulder lateral groove is smallest, between a ground contact surface and a groove bottom of the shoulder lateral groove. A width of the shoulder sipe may not be greater than 1.5 mm. An internal groove having a groove width greater than the width of the shoulder sipe can be continuously disposed inwardly of the shoulder sipe in a tire radial direction. The internal groove can be disposed inwardly of the minimal portion and outwardly of the groove bottom of the shoulder lateral groove, in the tire radial direction.

A pneumatic tire is provided which has sufficiently reduced rolling resistance during high-speed running and which has sufficiently improved durability. In this pneumatic tire, which has a tread, at least one rubber layer forming the tread includes a rubber component containing styrene butadiene rubber and isoprene rubber, and is formed from a rubber composition with a loss tangent (30° C. tan δ) less than or equal to 0.14, measured under the conditions of 30° C., frequency 10 Hz, initial strain 5%, and dynamic strain rate 1%; defining Wt (mm) as the cross-section width, Dt (mm) as the outer diameter and virtual volume V (mm3) as the volume of the space occupied by the tire when said tire is installed on the standardized rim and has an internal pressure of 250 kPa, the pneumatic tire satisfies (Formula 1) and (Formula 2).

1600≤(Dt.sup.2×π/4)/Wt≤2827.4  (Formula 1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (Formula 2)

The present invention provides a pneumatic tire which is sufficiently reduced in the rolling resistance during high-speed travel, while having sufficiently improved chipping resistance. A pneumatic tire which has a tread part, wherein: at least one rubber layer that forms the tread part contains a rubber component that contains an isoprene rubber, a styrene butadiene rubber and a butadiene rubber, while containing more than 5 parts by mass but 25 parts by mass or less of carbon black relative to 100 parts by mass of the rubber component; and if Wt (mm) is the cross-sectional width of the tire, Dt (mm) is the outer diameter of the tire, and V (mm.sup.3) is the virtual volume that is the volume of the space occupied by the tire when this pneumatic tire is installed on a standardized rim and the internal pressure is 250 kPa, (formula 1) and (formula 2) are satisfied.

1700≤(Dt.sup.2×π/4)/Wt≤2827.4  (formula 1)

[(V+1.5×10.sup.7)/Wt]≤2.88×10.sup.5  (formula 2)

A pneumatic tire includes lug grooves arranged in a circumferential direction in a tread surface of a land portion defined by two main grooves adjacent in a lateral direction, the lug grooves each crossing the circumferential direction and communicating at both ends with the main grooves, defining the land portion in the circumferential direction. A notch portion is formed on an opening edge of the lug grooves. The notch portion is cutout from the tread surface inward in a radial direction. The lug grooves have a maximum groove width at a position from 30% to 70% of a lateral direction dimension of the land portion from one of the main grooves and a groove width that decreases from the maximum groove width to the main grooves. The notch portion has a notch width that increases from a position of the maximum groove width of the lug grooves to the main grooves.