Patent ID: 6907909

Claim:
A pneumatic tire comprising a tread portion with a tread pattern defined by a plurality of slant grooves, each of which slant grooves comprising a steeply slant groove portion located in a widthwise central region of the tread portion, inclined at a relatively small angle with respect to a circumferential direction of the tire, and extending from a top that is one end of the steeply slant groove portion which is close to an equatorial plane of the tire toward an end that is the other end of the steeply slant groove portion which is close to a tread end, and a gently slant groove portion located in each of both side regions of the tread portion, inclined at a relatively large angle with respect to the circumferential direction of the tire, and extending from the end of the steeply slant groove portion or an extension thereof so as to open at the tread end, the improvement wherein: an opening groove width (W 1 ) located at the other end of the steeply slant groove portion is wider than an opening groove width (W 2 ) located at the top of the steeply slant groove portion; the steeply slant groove portion extending in a longitudinal direction of the slant groove comprises a groove edge part forming a boundary to an outer surface of a tread land portion, a main groove bottom part mainly forming a groove bottom of the steeply slant groove portion, and a pseudo-land part arranged in the steeply slant groove portion and extending along the groove edge part and adjacent to at least one of both side edges of the main groove bottom part, wherein the pseudo-land part is adapted to strengthen an acute zone of a tread land portion and to smoothly move water from the steeply slant groove portion to the gently slant groove portion; the pseudo-land part is defined by a slant surface that a height thereof is gradually decreased in the tire widthwise direction from the groove edge part toward the main groove bottom part and is gradually decreased in the forward rotation direction of the tire toward the main groove bottom part; the pseudo-land part is longer in the circumferential direction than it is wide in the tire widthwise direction; and the width of the pseudo-land part varies along its circumferential length.