Patent ID: 8759262

Claim:
A lubricating oil composition comprising: (a) a major amount of oil of lubricating viscosity; (b) at least one phenate detergent having, or having on average, a TBN of from about 50 to about 150 mg KOH/g, in an amount providing at least 1.4 grams of phenate soap per 100 grams of lubricating oil composition; and (c) at least one sulfonate detergent having, or having on average, a TBN of from about 150 to about 475 mg KOH/g; wherein the ratio of the amount of phenate soap, in grams of phenate soap per kilogram of lubricating oil, to the amount of sulfonate soap, in grams of sulfonate soap per kilogram of lubricating oil composition, is from about 5:1 to about 20:1; and wherein the lubricating oil composition has a sulfur content of no more than 0.4 mass %, a phosphorus content of from about 0.03 mass % to no more than 0.12 mass % and an ash content of no more than 1.1 mass % and contains no more than 0.5 grams of carboxylate soap per 100 grams of lubricating oil composition.