Abstract: A pneumatic tire having a tread surface provided with a plurality of circumferential grooves and lateral grooves each having one end opened into that circumferential groove and the other end terminating in a land portion. At least one lateral groove is always included completely in the ground contact surface of the tread. The groove width of the lateral grooves is at least locally not less than 30% of the groove width of the circumferential grooves. Each lateral groove has an extending length not less than 40% of an extending length of the circumferential grooves in the ground contact surface and is provided with a region having a cross-sectional area which increases from its side of opening into the circumferential groove toward its terminal end, and including a starting end with a minimum cross-sectional area that is situated closer to the circumferential groove in which the lateral groove opens.

Abstract: A pneumatic tire sufficiently enhances the frequency dispersion effect for the columnar resonance noise due to the presence of the circumferential grooves, per se, or the lowering effect for the sound pressure level, in association with the cross-sectional area of the lateral grooves. The tire has a tread surface provided with a plurality of circumferential grooves (2, 4) extending continuously in a circumferential direction. The circumferential grooves (2, 4) are each provided with a plurality of lateral grooves (7, 8) each having one end opened into that circumferential groove and the other end terminating in a land portion (7, 8), independently from other circumferential grooves, other lateral grooves opening into said other circumferential grooves or in a ground contacting end of a tread.

Abstract: An object is to provide a pneumatic tire having an enhanced high-speed durability without deterioration in steering stability. A pneumatic tire 10 includes a belt 14 and a tread section 16 on an outside of a crown part 12C in this order, and has different negative ratios of the tread section 16 between both sides of a tire equatorial plane 10C. A belt width Ba from a belt end 14I on the higher negative ratio side to the tire equatorial plane 10C and a belt width Bb from a belt end 14E on the lower negative ratio side to the tire equatorial plane 10C satisfy a relationship of Ba>Bb. It is thereby possible to efficiently suppress a shoulder section 18 from projecting due to a centrifugal force during high-speed rolling. It is thereby possible to efficiently reduce a strain and a heat generated in a rubber member of the shoulder section 18, and efficiently enhance high-speed durability.