The present invention is directed to a pneumatic tire 1, comprising at least one pair of parallel annular beads 3; at least one carcass ply wrapped 5 around said beads 3; a tread 7; and first and second sidewalls 9 disposed between said tread 7 and one of said at least one pair of beads 3. In accordance with an embodiment of the invention, the tread comprises tread blocks 11 and/or tread ribs 12, wherein the tread blocks 11 and/or tread ribs 12 comprise sipes 13 extending essentially in an axial direction A of the tire 1, the sipes 13 consisting of an upper portion 15 essentially aligned with the radial direction R of the tire and a lower portion 17 inclined in the direction of rotation D of the tire 1.