Abstract: The invention comprises a novel stabilizing system useful for imparting resistance to oxidative breakdown comprising:(1) a metal deactivator azine of the formula: ##STR1## where: R.sub.1 and R.sub.2 can be hydrogen, alkyl with 1-12 carbon atoms, alkoxy with 1-12 carbon atoms, carbalkoxy with 1-12 carbon atoms, halogen, hydroxy, nitro and amino groups and X.sub.1 and X.sub.2 can be hydrogen, alkyl with 1-12 carbon atoms or di-, tri- or tetramethylene bridges to the aromatic ring.(2) an amine;(3) a metal compound selected from the group consisting of metals or metal salt; and(4) a lubricating oil selected from the group consisting of mineral oils or synthetic hydrocarbon oils.

Abstract: Lubricating oils are stabilized against oxidative degradation by the use of a stabilizer comprising (A) an amine wherein the amine is a substituted benzylamine, or a substituted 1-amino-1,2,3,4-tetrahydronaphthalene, (B) a metal deacturator and (C) a metal or metal salt. Optionally a metal deactivator can be incorporated into the system. The preferred substitute benzylamine is N(alpha-methyl benzyl)amine the preferred naphthalamine is phenyl-alpha-naphthalamine.