Patent ID: 8524645

Claim:
A lubricant composition comprising: an oil of lubricating viscosity; (A) about 0.2 to about 1 percent by weight of a copolymer comprising about 70 to about 79 percent by weight of units derived from ethylene (“E”), having a M w of about 70,000 to about 95,000, M w / M n less than about 3, density (“D”) of about 860 to about 896 kg/m 3 , and a melting point (“T m ,”) of about 15° C. to about 60° C., wherein E and T m fulfill the expression 3.44 E− 206 ≧T m ; wherein the copolymer (A) is an ethylene/propylene copolymer; and (B) about 0.4 to about 1.5 percent by weight of a block copolymer comprising a first block which comprises a vinyl aromatic comonomer comprising styrene and a second block which comprises a diene comonomer comprising isoprene or 1,3-butadiene, the diene monomer-containing block being hydrogenated; wherein the vinyl aromatic content of the block copolymer (B) is about 20 to about 40 weight percent and wherein the weight average molecular weight of the polymer (B) is about 100,000 to about 300,000; wherein the weight ratio (A):(B) is about 20:80 to about 60:40, wherein the block copolymer (B) comprises at least one homopolymer or homo-oligomer segment of the vinyl aromatic monomer, and wherein the block copolymer (B) is other than a star polymer.