Lubricating compositions containing a synergistic mixture of additives

A lubricating composition comprises a base oil and (a) a phosphosulphurized hydrocarbon further reacted with an alkylene oxide and (b) a non-metal containing oil-soluble copolymer derived from two or more unsaturated co-polymerizable monomers, at least one being an anhydride of an a ,p-unsaturated polycarboxylic acid or a partial ester thereof wherein the remaining acid groups are free. Lists of suitable monomers, and the hydrocarbons which can be phosphosulphurized are given. The base oil mineral, cutting including emulsified oils, hydraulic fluids and synthetic oils, e.g. oxidized mineral oils, mono-, di- and complex esters, castor oil or fish oils. In addition, phenthiazine and its alkyl derivatives, a - or b -naphthylamine substituted diphenylamines, alkyl phenols, bisphenols, phosphates and phosphites, sulphurized hydrocarbons and sperm oil, metal dialkyl dithiophosphates, polyisoolefines and degraded rubbery copolymers.