Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties, formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and a dialkyldisulfide.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing an alkylphenyl or alkarylphenyl naphthylamine, a dialkyldiphenylamine, a polyhydroxyanthraquinone, a hydrocarbyl phosphate ester and a thiadiazole derivative mixture as hereinafter defined.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties, formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a phenylnaphthylamine, a dialkyldiphenylamine, a hydrocarbyl phosphate ester, a polyhydroxy anthraquninone, an alkylamine salt of 3-amino-triazole-dodecenylsuccinamic acid, 2-hydroxylpropyl-N,N-dibutyldithiocarbamate, and an alkyl amine salt of a methyl acid phosphate.

Abstract: Lubricating oil composition comprising a major portion of an aliphatic ester base oil having lubricating properties formed from the reaction of pentaerythritol and an organic monocarboxylic acid containing (a) from about 0.005 to 0.20 percent of a 2,5-bis(alkylthio)-1,3,4-thiadiazole; (b) from about 0.3 to 5 percent of an alkyl or alkaryl phenylnaphthylamine; (c) from about 0.3 to 5 percent of a dialkyldiphenylamine; (d) from about 0.25 to 10 percent of a hydrocarbyl phosphate ester, and (e) from about 0.04 to 2 weight percent of a polyhydroxy-substituted anthraquinone.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and a thioacid derivative compound as hereinafter described.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties, formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and a dialkyl sulfide compound as hereinafter described.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base fluid having lubricating properties, formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a hydrocarbyl phosphate ester, a polyhydroxy anthraquinone, a dialkyl sulfide and either a phenylnaphthylamine or a dialkyldiphenylamine.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and an organic sulfur containing compound as hereinafter described.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing a phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and an alkyl thioacid ester.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed from the reaction of pentaerythritol and an organic monocarboxylic acid, and containing an alkylphenyl or alkarylphenyl naphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and an S-alkyl-2-mercaptobenzimidazole.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed from the reaction of pentaerythritol and an organic monocarboxylic acid, and containing an alkylphenyl or alkarylphenyl naphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and an S-alkyl-2-mercaptobenzothiazole.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed from the reaction of pentaerythritol and an organic monocarboxylic acid, and containing an alkylphenyl or alkarylphenyl naphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and a N-(alkyl)-benzothiazole-2-thione.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed by the reaction of pentaerythritol and an organic monocarboxylic acid and containing an alkylphenyl or alkaryl phenylnaphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and an aromatic substituted thiophene.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed from the reaction of pentaerythritol and an organic monocarboxylic acid, and containing an alkylphenyl or alkarylphenyl naphthylamine, a dialkyldiphenylamine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester and a bis (dialkylthiocarbamyl) sulfide.

Abstract: Synthetic lubricating oil composition having improved oxidation stability comprising a major portion of an aliphatic ester base oil having lubricating properties formed by the reaction of a pentaerythritol and an organic monocarboxyic acid and containing an alkyl phenyl- or alkarylphenyl-naphthylamine, a dialkyldiphenyl-amine, a polyhydroxy anthraquinone, a hydrocarbyl phosphate ester, 4,4'-dithiodimorpholine and 3-aminotriazole.