A lubricating oil composition for internal combustion engines, including a lubricant base oil and 3% by mass or more, but less than 40% by mass of a liquid random copolymer of ethylene and an α-olefin, the liquid random copolymer being produced using a specific catalyst, wherein the lubricating oil composition has a kinematic viscosity at 100° C. of 6.9 mm.sup.2/s or more, but less than 12.5 mm.sup.2/s, and wherein the lubricant base oil consists of a mineral oil having a kinematic viscosity at 100° C. of 2 to 7 mm.sup.2/s, a viscosity index of 105 or more and a pour point of −10° C. or lower, and/or a synthetic oil having a kinematic viscosity at 100° C. of 1 to 7 mm.sup.2/s, a viscosity index of 120 or more and a pour point of −30° C. or lower.

A polymeric material mixture comprising a fluorine-containing polymer, a siloxane polymer, and at least two polymer processing additives (PPA), wherein the at least two polymer processing additives have different chemistries. For example, there can be a flexible coextruded pipe for providing a protective housing for cables, fluids, sludge or solids, the pipe comprising a pair of telescopically related inner and outer layers, where said inner layer is lubricated with the polymeric material mixture.

A viscosity index improver comprising a reaction product of (i) an acylated copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having an Mn of 3,000 to 250,000 g/mol; and (ii) a compound of the formulae (III)-(V): ##STR00001##
wherein R.sub.6, R.sub.8, R.sub.9, R.sub.10, R.sub.12 and R.sub.15 are independently selected from a hydrogen and an optionally substituted linear or branched alkyl or alkenyl group, and R.sub.7, R.sub.11, R.sub.13, R.sub.14, R.sub.16, and R.sub.17 are independent selected from an optionally substituted linear or branched alkyl or alkenyl group, and a sum of the number of carbon atoms in each compound of the formulae (III)-(V) is from 6 to 31.

A viscosity index improver comprising a reaction product of (i) an acylated copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having an Mn of 3,000 to 250,000 g/mol; and (ii) a compound of the formulae (III)-(V): ##STR00001##
wherein R.sub.6, R.sub.8, R.sub.9, R.sub.10, R.sub.12 and R.sub.15 are independently selected from a hydrogen and an optionally substituted linear or branched alkyl or alkenyl group, and R.sub.7, R.sub.11, R.sub.13, R.sub.14, R.sub.16, and R.sub.17 are independent selected from an optionally substituted linear or branched alkyl or alkenyl group, and a sum of the number of carbon atoms in each compound of the formulae (III)-(V) is from 6 to 31.

A viscosity index improver comprising a reaction product of (i) an acylated copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having an Mn of 3,000 to 250,000 g/mol; and (ii) a compound of the formulae (III)-(V):

##STR00001##

wherein R.sub.6, R.sub.8, R.sub.9, R.sub.10, R.sub.12 and R.sub.15 are independently selected from a hydrogen and an optionally substituted linear or branched alkyl or alkenyl group, and R.sub.7, R.sub.11, R.sub.13, R.sub.14, R.sub.16, and R.sub.17 are independent selected from an optionally substituted linear or branched alkyl or alkenyl group, and a sum of the number of carbon atoms in each compound of the formulae (III)-(V) is from 6 to 31.

A viscosity index improver comprising a reaction product of (i) an acylated copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having an Mn of 3,000 to 250,000 g/mol; and (ii) a compound of the formulae (III)-(V):

##STR00001##

wherein R.sub.6, R.sub.8, R.sub.9, R.sub.10, R.sub.12 and R.sub.15 are independently selected from a hydrogen and an optionally substituted linear or branched alkyl or alkenyl group, and R.sub.7, R.sub.11, R.sub.13, R.sub.14, R.sub.16, and R.sub.17 are independent selected from an optionally substituted linear or branched alkyl or alkenyl group, and a sum of the number of carbon atoms in each compound of the formulae (III)-(V) is from 6 to 31.

A lubricating oil composition may be used for lubrication of a shock absorber, and may include a base oil (A), a polyalkyl (meth)acrylate (B) having a weight average molecular weight in a range of from 150,000 to 900,000, and an olefin copolymer (C) having a weight average molecular weight of 100,000 or less.

A lubricating oil composition may be used for lubrication of a shock absorber, and may include a base oil (A), a polyalkyl (meth)acrylate (B) having a weight average molecular weight in a range of from 150,000 to 900,000, and an olefin copolymer (C) having a weight average molecular weight of 100,000 or less.

The present disclosure relates to methods of improving viscosity shear stability of a lubricating oil and lubricating oil composition comprising: a base oil of lubricating viscosity; an amount of one or more zinc dialkyl dithiophosphate compound(s);
wherein the lubricating oil composition has one or both of the following ratios: a) a ratio of KV40° C..sub.fresh to a weight % of zinc contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 510, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.; and b) a ratio of KV40° C..sub.fresh to a weight % of phosphorus contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 560, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.

The present disclosure relates to methods of improving viscosity shear stability of a lubricating oil and lubricating oil composition comprising: a base oil of lubricating viscosity; an amount of one or more zinc dialkyl dithiophosphate compound(s);
wherein the lubricating oil composition has one or both of the following ratios: a) a ratio of KV40° C..sub.fresh to a weight % of zinc contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 510, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.; and b) a ratio of KV40° C..sub.fresh to a weight % of phosphorus contributed by the one or more zinc dialkyl dithiophosphate compound(s) based on a total weight of the lubricating oil composition, of greater than 560, wherein KV40° C..sub.fresh is the kinematic viscosity of the fresh lubricating oil composition at 40° C.