Abstract: Thus, the instant invention is directed toward an oil for diesel engines comprising an admixture of (A) a major amount of an oil of lubricating viscosity, (B) at least 4 mass % dispersant, (C) at least 0.3 mass % of a metal phenate, (D) less than 0.1 mass % friction modifier, (E) less than 0.3 mass % of sulfurized phenols and, (F) less than 0.12 mass % neutral calcium sulfonate.

Abstract: A fluid having a mineral lubricating oil base and containing the combination of an oil-soluble tris (C.sub.8 -C.sub.24 hydrocarbyl) phosphite ester and an oil-soluble C.sub.8 -C.sub.24 hydrocarbyl substituted phenol, the weight ratio of said phosphite to said phenol ranging from about 4:1 to 1:4, preferably 3:1 to 1:3 whereby elastomer compatibility of said fluid is enhanced. The phosphite ester-substituted phenol combination imparts to the fluid the property of maintaining the chemical and physical properties of seals under oxidizing condition in automatic transmissions, power transmissions and power steering systems and thereby improves retention of the fluid in these mechanical structures; preferably when at least an inhibitory amount of an anti-oxidant capable of trapping free radicals at temperatures above 65.degree. C., preferably 80 .degree. to 200.degree. C. is present.

Abstract: Thus, the instant invention is directed toward an oil for diesel engines comprising an admixture of (A) a major amount of an oil of lubricating viscosity, (B) at least 4 mass % dispersant, (C) at least 0.3 mass % of a metal phenate, (D) less than 0.1 mass % friction modifier, (E) less than 0.3 mass % of ashless sulfurized phenols and, (F) less than 0.12 mass % neutral calcium sulfonate.