PNEUMATIC RADIAL TIRE

摘要

A pneumatic radial tire suitable for passenger car use which has a tread provided with four main grooves, each shoulder rib formed between the outermost main groove and the tread edge is provided with shoulder lateral grooves to be divided into blocks, each middle rib formed between the inner main groove and the outermost main groove is provided with middle lateral grooves to be divided into blocks, the central rib formed between the two inner main grooves is provided with central lateral grooves extending from the inner main grooves towards the tire equator and terminated in the central rib so as to provide continuity in the circumferential direction of the tire, in a state that the tire is mounted on its regular rim and inflated to its regular inner pressure and loaded with its regular tire load, the quotient (WG/W) of the total (WG) of the axial widths (WG1, WG2) of the four main grooves divided by the ground contact width (W) measured between the axial edges of the ground-contacting area is in the range of 0.25 to 0.32, and on each side of the tire equator, the ground contact width (W) and the total (LG1+LG2) of the axial length (LG1) measured from the ground contacting area edge to the axially inner edge of the shoulder rib and the axial length measured from the ground contacting area edge to the axially inner edge of the middle rib satisfies the following relation: 0.44 =< (LG1+LG2)/W =< 0.50.