A lubricant composition that is particularly suited for use in steam and gas turbine oils and in circulating oils has a balance of excellent oxidative stability and reduced sludge formation and comprises a blended mixture of alkylated phenyl-α-naphthylamine and at least oil soluble triazole or triazole derivative in an oil of lubricating viscosity, such compositions being capable of a residual RPVOT of 25% after at least 500 hours test duration test duration 120° C. in Dry TOST test or, alternatively 50% after 700 hours or 25% after 1000 hours.