Patent ID: 7028734

Claim:
A pneumatic tire comprising a tread, said tread comprising a tread cap and a tread base; said tread cap comprising, based on 100 parts by weight rubber (phr): 100 phr of cis 1,4 polyisoprene natural rubber; from about 25 to about 45 phr of carbon black; and from about 8 to about 35 phr of silica; said tread base comprising, based on 100 parts by weight rubber (phr): 100 phr of cis 1,4 polyisoprene natural rubber; from about 25 to about 50 phr of carbon black; and from about 8 to about 35 phr of silica; wherein said tread cap has a stiffness greater than that of said tread base, said stiffness characterized by a 300 percent modulus, said tread cap having a 300 percent modulus ranging from about 10 MPa to about 12 MPa and said tread base having a 300 percent modulus ranging from about 8 MPa to about 11 MPa; said tread comprising a tread base to tread cap volume ratio ranging from about 0.5 to about 1.