A lubricating composition, especially suitable for use in internal combustion engines, comprises a major proportion by weight of a lubricating oil and a minor proportion by weight, sufficient to enhance the detergent characteristics of the composition, of an additive consisting of a predominantly aliphatic or cycloaliphatic macromolecule, which macromolecule comprises up to 99,9% by weight of oil-solubilizing aliphatic or cycloaliphatic hydrocarbon groups and at least 0,1% by weight of one or more non-carboxylic-ester-linked polyglycol groups each having at least five alkylene oxide units with from two to seven carbon atoms in each alkylene oxide unit, said macromolecule having an average molecular weight of at least 50,000 and a solubility in the lubricating oil of at least 0,5% by weight. The lubricating oil may be a mineral oil, a synthetic hydrocarbon (e.g. a hydrogenated hydrocarbon, polymer, a chlorinated alkane/aryl compound condensation product or a high molecular weight alkylated hydrocarbon such as an alkylated wax), an alkylene oxide polymer or an etherification and/or esterification product thereof, or an ester such as di(2-ethylhexyl) sebacate, tricresyl phosphate or a silicate ester. The macromolecular additive may be a copolymer of (A) an oilsolubilizing olefin of 2-30 carbon atoms or a monomeric compound having a polymerizable ethylenic linkage and containing a hydrocarbyl group of 4-30 aliphatic or cycloaliphatic carbon atoms (e.g. an alkenyl ether, an alkenyl ester of a monocarboxylic acid, or an ester of an unsaturated mono- or di-carboxylic acid), (B) a noncarboxylic-ester-linked polyglycol monomeric compound having a polymerizable ethylenic linkage and a polyglycol group containing at least 5 alkylene oxide units in which each alkylene oxide unit has 2-7 carbon atoms and, optionally, (C) a monomeric polar compound having a polymerizable ethylenic linkage and a polar group (e.g. -COOH, -CONH2, -CONH-ROH or -CONHRNH2 where R is alkylene, carboxyl groups esterified with hydroxy- or amino-substituted alkyl groups, heterocyclic nitrogenous groups, epoxy groups and cyano groups). In monomer (B), the polyvalent linking group or atom between the group bearing the polymerizable ethylenic linkage and the polyglycol group may be -0-, -5-, or a carbonyl, sulphonyloxy, iminocarbonyl, ureylene, iminocarbonyloxy, phosphonyloxy or imino group. Specific examples of monomers (B) are polyglycol amides of unsaturated mono- or dicarboxylic acids and vinyl or allyl monoethers of polyglycols. However, methods other than copolymerization may be used in preparing the macromolecular additive. Specific macromolecular additives mentioned as suitable for addition to mineral lubricating oil are (i) the copolymer of dodecyl methacrylate and methacrylamide-initiated or allylamine-initiated polyethylene glycol, (ii) the copolymer of dodecyl methacrylate and polyethylene glycol monovinyl ether, (iii) the phosphonate product formed by reacting chlorophosphonylated polyisobutylene with the dodecyl mono-ether of polyethylene glycol and (iv) the sulphonate product formed by reacting chlorosulphonylated polyisobutylene with the dodecyl mono-ether of polyethylene glycol. The lubricant composition may contain additional ingredients such as pour point depressants, oiliness and extreme pressure agents, antioxidants and corrosion inhibitors (e.g. P2S5-treated pinene and divalent metal salts of organic dithiophosphoric acids), blooming agents, thickening agents, viscosity improvers (e.g. alkyl methacrylate polymers or butene polymers) or auxiliary detergents and antiwear agents (e.g. alkaline earth phenates of higher alkyl phenols).ALSO:An additive for lubricating oils (see Group III) consists of a predominantly aliphatic or cycloaliphatic macromolecule which comprises up to 99,9% by weight of oil-solubilizing aliphatic or cycloaliphatic hydrocarbon groups and at least 0,1% by weight of one or more non-carboxylic-ester-linked polyglycol groups each having at least 5 alkylene oxide units with 2-7 carbon atoms in each alkylene oxide unit, said macromolecule having an average molecular weight of at least 50,000 and a solubility in the lubricating oil of at least 0,5% by weight. The additive may be a copolymer of (A) an oil-solubilizing olefin of 2-30 carbon atoms or a monomeric compound having a polymerizable ethylenic linkage and containing a hydrocarbyl group of 4-30 aliphatic or cycloaliphatic carbon atoms (e.g. an alkenyl ether, an alkenyl ester of a monocarboxylic acid or an ester of an unsaturated mono- or di-carboxylic acid), (B) a non-carboxylic-ester-linked polyglycol monomeric compound having a polymerizable ethylenic linkage and a polyglycol group containing at least 5 alkylene oxide units in which each alkylene oxide unit has 2-7 carbon atoms and, optionally, (C) a monomeric polar compound having a polymerizable ethylenic linkage and a polar group (e.g. -COOH, -CONH2, -CONHROH or -CONHRNH2 where R is alkylene, carboxyl groups esterified with hydroxy- or amino-substituted alkyl groups, heterocyclic nitrogenous groups, epoxy groups and cyano groups). In monomer (B), the polyvalent linking group or atom between the group bearing the polymerizable ethylenic linkage and the polyglycol group may be -O-, -S-, or a carbonyl, sulphonyloxy, iminocarbonyl, ureylene, imino carbonyloxy, phosphonyloxy or imino group. Specific examples of monomers (B) are polyglycol amides of unsaturated mono- or di-carboxylic acids and vinyl or allyl monoethers of polyglycols. However, methods other than copolymerization may be used in preparing the macromolecular additive. In the examples, the preparation is described of (i) the copolymer of dodecyl methacrylate and methacrylamide-initiated or allylamine-initiated polyethylene glycol, (ii) the copolymer of dodecyl methacrylate and polyethylene glycol monovinyl ether, (iii) the phosphonate product formed by reacting chlorophosphonylated polyisobutylene with the dodecyl mono-ether of polyethelene glycol and (iv) the sulphonate product formed by reacting chlorosulphonylated polyisobutylene with the dodecyl monoether of polyethylene glycol.