Carboxylate-vinyl ester copolymer blend compositions for lubricating oil flow improvement

A lubricating oil composition comprising a dual additive composition in an amount and additive ratio effective to improve, relative to the absence of one or more components of said dual additive composition, at least the low temperature flow properties of said lubricating oil composition when said lubricating oil composition comprises at least one lubricating oil basestock selected from the group consisting of lubricating oils of greater than or equal to 90 wt. % saturates and less than or equal to 0.03 wt. % sulfur and a viscosity index in the range of greater than or equal to 80 and less than about 200, and at least one viscosity index improver selected from the group consisting of copolymers of ethylene and at least one C3 to about C18 alphaolefin, wherein the ethylene content of said ethylene containing copolymer is greater than about 30 wt. % to about 85 wt. %, said dual additive composition comprising a mixture of:

• (A) first added lubricating oil flow improver component containing pendent ester groups having repeating methylene units derived from a mixture of alcohols present within the structure of said pendant ester groups, comprising a copolymer of (i) a first monomer of an ester of an unsaturated dicarboxylic acid or its corresponding anhydride having the formula:
• wherein R is selected from the group consisting of from about C6 to about C24 alkyl group provided that the average side chain carbon number is between 11.5 and 12.2 and (ii) a second monomer selected from the group consisting of (a) vinyl ester represented by the formula:
• wherein R1 comprises an alkyl group containing from 1 to about 18 carbon atoms, (b) about C6 to about C46 straight or branched chain alpha-monoolefin, and (c) styrene;
• or a polymer or copolymer of unsaturated mono-ester represented by the formula:
• wherein R3 is hydrogen or a C1 to C5 alkyl group;
• and R4 is a COOR5 group wherein R5 is a C1 to C20 alkyl, with the proviso that the average number of carbon atoms in the groups constituting R5 in the polymer or copolymer is between 11.5 and 12.2, and
• (B) second added lubricating oil flow improver component containing pendent ester groups having repeating methylene units derived from a mixture of alcohols present within the structure of said pendant ester groups, comprising a copolymer of (i) unsaturated dicarboxy ester having the formula:
• wherein R2 is selected from the group consisting of from about C6 to about C24 alkyl group provided that the average side chain carbon number is between 12.7 and 15.0 and (ii) a second monomer selected from the group consisting of said second monomers set forth in (A)(ii), provided however, that when the second monomer corresponds to formula (IV) then the average number of carbon atoms in the groups constituting R5 in the polymer or copolymer is between 12.7 and 15.0;
• and
• wherein the weight ratio of said first component to said second component in said composition is from about 95:5 to about 40:60.