Oils such as gasoline, kerosene, fuel oil, gas oil, dioctyl adipate, dinonyl sebacate, castor oil, olive oil, sesame seed oil and mineral oils, as well as lubricating greases, contain as antioxidant an oil miscible butylated bisphenol prepared in a particular manner (see Division C2). Lubricating oils may contain additionally Ba, Ca, Pb, Zn and Ni diorganophosphorodithioates; P2S5-treated olefins and terpenes; alkyl phenolates; alkyl phenolate (alkaline earth metal) sulphides; sulphur chloride treated or sulphurized olefins; phenolates of phenolformaldehyde condensates; p-aminophenol, N-alkylated phenylenediamines and anthrasilic acid (or esters); metal salts of P2S5-treated polyethylenes, polypropylenes and polyisobutenes; borate esters and boric acid treated amines, amides and imides: organic phosphites and phosphates; polymerized dimethyl silicones; wax-alkylated naphthalene; polyacrylates and polymethacrylates; lard oil; oleic acid and amide; glyceryl dioleates; polyisobutenes; hydrocarbon sulphides and polysulphides; halogenated aliphatic and cycloaliphatic compounds; sulphurized esters; vinyl-pyrrolidone or -pyridine/acrylate or methacrylate copolymers; polyisobutene-substituted succinic anhydride/alkylene amine reaction products which may contain boron; dithiocarbamic acid esters and salts; xanthic acid esters and salts. Many of such additives are described in further detail. Specified lubricants contain besides the butylated bisphenol and a motor oil: (a) P2S5-treated turpentine and Zn dioctyl phosphorodithioate, (b) Ca isooctylphenolate monosulphide, or (c) polyisobutene-substituted succinic anhydride/tetraethylenepentamine reaction product.ALSO:Butylated bisphenols are obtained by condensing at least 2 equivalents of phenol with formaldehyde (or a substance yielding it) in presence of an ionic catalyst of pH below 6.5 in water at 20 DEG C., heating the product to remove water and uncondensed phenol and alkylating the methylene-bridged phenol residue with at least 1.5 equivalents of isobutene per equivalent of phenolic OH in presence of an acid catalyst. The products may be used as antioxidants for e.g. dioctyl adipate or dinonyl sebacate.ALSO:Materials such as asphalt, national and synthetic rubbers, polyethylene and polyvinyl chloride contain as antioxidant an oil-miscible butylated bisphenol prepared in a particular manner (see Division C2). In an example, P.V.C. contains additionally dioctyl phthalate.