Functional fluids useful at high temperatures

A high temperature lubricating composition which comprises

• (A) at least about 85% by weight of at least one liquid synthetic base oil selected from the group consisting of polyol esters, hydrogenated polyalphaolefins, esters of aromatic phosphorus acids and mixtures thereof;
• (B) from about 0.1 to about 10% by weight of at least one neutral or basic alkaline earth metal salt of an alkyl phenol sulfide prepared by reacting an alkyl phenol with sulfur monochloride, sulfur dichloride or elemental sulfur, an alkylene coupled phenol, prepared by reacting a phenol with an aldehyde or ketone or mixtures thereof;
• and
• (C) from about 0.01 to about 10% by weight of at least one non-phenolic organic antioxidant.

A lubricating composition useful at temperatures above about 260.degree. C. and which comprises

• (A) at least about 85% by weight of a synthetic base oil which comprises at least one synthetic polyol ester;
• (B) from about 0.1 to about 10% by weight of at least one basic alkaline earth metal salt of an alkyl phenol sulfide prepared by reacting an alkyl phenol with sulfur monochloride, sulfur dichloride or elemental sulfur;
• and
• (C) from about 0.01 to about 10% by weight of at least one aromatic secondary amine represented by the formula
• R.sup.3 R.sup.4 NH (III)
• wherein R.sup.3 and R.sup.4 are each independently hydrocarbon-substituted aromatic groups.