Patent ID: 8470751

Claim:
An internal combustion engine crankcase lubricating oil composition having a phosphorus concentration, expressed as atoms of phosphorus, of from about 0.01 to not greater than 0.08 mass %, based on the mass of the oil composition, which composition comprises or is made by admixing: A. an oil of lubricating viscosity, in an amount of at least 80% by weight based on the total weight of the composition; and B. a metal detergent system, in an amount providing from 1,600 to 3,000 ppm by mass of atoms of calcium and of magnesium, based on mass of the oil composition, consisting essentially of a calcium salicylate and magnesium salicylate and having a mass ratio of magnesium atoms to calcium atoms of from 10:6 to 5:1.