Tire tread formulation

A tire which is comprised of a generally toroidal-shaped carcass with an outer circumferential tread which is adapted to be ground contacting, two spaced beads, at least one ply extending from bead to bead and sidewalls extending radially from and connecting said tread to said beads, wherein the circumferential tread is comprised of (1) about 10 phr to about 70 phr of a solution styrene-butadiene rubber having a glass transition temperature which is within the range of from about −85° C. to about −20° C., a bound styrene content which is within the range of from about 10 to about 40 percent,;

• (2) about 0 phr to about 50 phr of emulsion styrene-butadiene rubber having a glass transition temperature which is within the range of from about −65° C. to about −45° C. and having a bound styrene content which is within the range of 15 to about 30 percent, and (3) about 20 phr to about 60 phr of cis-1,4-polybutadiene rubber having a cis-1,4-microstructure content of at least about 95 percent and having a glass transition temperature which is within the range of −90° C. to −110° C.;
• (4) 50 phr to 250 phr of an amorphous synthetic precipitated silica;
• and (5) from 2 phr to about 10 phr rubber reinforcing carbon black, wherein said precipitated silica is treated with 3 phf to 6 phf of a silica coupling agent.