Lubricant composition containing antioxidant

A lubricant composition comprising a lubricant base stock to which has been added an oxidation-inhibiting amount of the reaction product of an alkyl-substituted 1,2-dihydroquinoline with a diarylamine wherein the lubricant base stock is selected from the group consisting of a hydrocarbon-based oil, a mineral oil, a synthetic oil, an oil derived from coal or shale, a silicone-based oil, a crankcase lubrication oil for spark-ignited internal combustion engines, a crankcase lubricating oil for compression-ignited internal combustion engines, a transmission fluid, a transaxle lubricant, a gear lubricant, a metal-working lubricant, a hydraulic fluid, a grease, and miscible mixtures thereof.