High performance pneumatic radial tires

A high performance pneumatic radial tire comprising;

• a toroidal carcass, a tread radially outside a crown portion of the carcass ad having at least two circumferential main grooves, a belt layer interposed between the carcass and the tread and having substantially a same width of the tread, an auxiliary layer arranged between the belt layer and radially inwardly of groove bottoms of said circumferential main grooves and covering the entire belt layer, said auxiliary layer constituted by at least two auxiliary plies comprising one auxiliary ply which is located on a radially innermost side and covers the belt layer over an entire width thereof, and at least a radially outermost auxiliary ply which is discontinuous at locations overlapping the circumferential main grooves, organic cords of the auxiliary layer being buried substantially parallel to an equatorial plane of the tire, and land portions being defined between at least two of said circumferential main grooves formed in an outer surface portion of the tread and between the circumferential main grooves and axially opposite edges of the tread, wherein circumferential rigidity of portions of the auxiliary layer corresponding to the circumferential main grooves is smaller than that of at least a portion of said auxiliary layer corresponding to land portions in an axially central portion of said tread and axially opposite edges of said tread.