Pneumatic tire tread

A pneumatic radial passenger tire having a tread portion provided with a pair of tread edges spaced apart axially of the tire, the tread portion being provided with a plurality of main grooves associated with each tread edge, each of the main grooves following substantially identical paths, each of said main grooves having an axially outer end which opens outwardly of the associated tread edge and an axially inner end which terminates at a distance from said associated tread edge of at least forty percent (40%) of the tread width, the main grooves at their associated tread edges being spaced apart in a direction circumferentially of the tire a distance between twenty percent (20%) and forty percent (40%) of the tread width, the main grooves associated with any one tread edge extending from the axially outer end thereof in a generally curvilinear path axially inwardly and circumferentially of the tire with the main grooves associated wth any one tread edge extending in the same direction circumferentially of the tire, the center of curvature of each main groove being disposed on the side thereof facing in the direction of the respective associated tread edge, each main groove having a first branch and a second branch extending therefrom in a generally opposite circumferential direction from that which said main grooves extend, each first branch extending from its main groove towards and terminating in communication with the next circumferentially adjacent groove, the juncture of said first branch and its main groove being spaced from the associated tread edge a distance of between zero percent (0%) and ten percent (10%) of the tread width TW, the juncture of each first branch and the next circumferentially adjacent main groove being spaced from the associated tread edge a distance of between fifteen percent (15%) and thirty percent (30%) of the tread width, each second branch extending from its main groove past the next circumferential adjacent main groove towards at least and in close proximity with the second next circumferential main groove but not past the second next circumferentially adjacent main groove, the juncture of each second branch and its respective main groove being spaced from the associated tread edge a distance of between ten percent (10%) and thirty percent (30%) of the tread width, the axially inner end of each said second branch being spaced from its associated tread edge a distance of at least forty percent (40%) of the tread width, the included angle formed between the centerline of each main groove and the centerline of its first branch at the juncture thereof being no greater than about 30 degrees, the included angle formed between the centerline of each main groove and the centerline of its second branch at the juncture thereof being no greater than about 30 degrees, the main grooves, first branches and second branches providing the majority of grooves in the tread.