All season pneumatic tire

An all season pneumatic tire comprising a tread section including only two main grooves (3) dividing the tread width into three tread regions formed substantially in a circumferential direction and in a continuous arrangement, each of said two main grooves (3) having a groove width (GW) and a center block (6) therebetween, and a distance (GD) includes one of the two main grooves (3) and a tread section between the two main grooves (3), when the maximum tire width is (TW), is expressed as:

• 0.2TW.ltoreq.GD.ltoreq.0.5TW,
• and the width (GW) of each said main groove (3) is expressed as:
• 0.02TW.ltoreq.GW.ltoreq.0.07TW;
• each of said main grooves (3) being provided with two opposed side walls, the side walls being substantially parallel to the circumferential direction of the tire with jogs (JW) shifted thread-width-wise by a distance the same as or smaller than the groove width (GW), said jog width (JW) being expressed as:
• 0.5 mm.ltoreq.JW.ltoreq.GW,
• and being formed substantially, in a circumferential direction and in a continuous arrangement, between the two main grooves (3), inclined grooves (4) are provided which are extended tread-width-wise to connect the two main grooves (3) and with interconnecting grooves (5) extended in circumferential direction to connect said inclined grooves, side blocks being formed tread-width-wise at both side areas outside the main grooves (3), said side blocks (9) comprising sideways grooves (8) extending in the tread-width-wise direction and spaced a predetermined distance from one another in the circumferential direction, sips (7A) extending generally perpendicularly from the inclined grooves (4) and sipes (7) extending generally perpendicularly from the interconnecting grooves (5) and said side blocks (9) possess sipes (11) extended tread-width-wise and sipes (10) extended in the circumferential direction, inclined slits (12), (13) being formed on elevated walls of the main groove (3) which extend tread-width-wise and are positioned approximately at the center of clocks (6), (9) with intervals disposed in the circumferential direction.