Pneumatic tire therad with wide central groove and arcuate grooves

A tire comprising a carcass of reinforcement material having cords oriented at an angle from about 75.degree. to 90.degree. with respect to the mid-circumferential centerplane of the tire and a ground engaging tread portion extending circumferentially about said carcass reinforcement material, the interior surface of the crown portion of said tire being continuously concave when viewed from the axis of rotation of the tire, said tread portion having a substantially straight depression therein that extends circumferentially about the tire such that a centerline of the depression does not vary a distance of more than five percent of the effective tread width from the mid-circumferential centerplane of the tire, said depression having a contact width equal to or greater than ten percent of the contact width of said tread portion as measured from a footprint of the tire, a plurality of substantially axially extending grooves extending axially outwardly from each side of said depression to the respective tread edges, each axially extending groove being oriented such that it forms an angle of approximately forty-five degrees or greater at the point where it merges with the depression and increases in a substantially continuous manner so as to be substantially perpendicular as it reaches the tread edge, a sufficient number of axially extending grooves are provided so that at least three grooves on each side of said depression are in a footprint of the tire, said tread portion having a net to gross ratio in the range of 50 to 65, said tread portion having a tread width equal to or greater than approximately ninety percent of the maximum section width of the tire, said tread portion having a radius equal to or greater than the circumferential radius of the tire as measured at the mid-circumferential centerplane of the tire, said tire having as aspect ratio of not greater than 0.60, and said depression and axially extending grooves having depths equal to or less than 0.2 inches.