Patent ID: 8841243

Claim:
A method for preventing or inhibiting exhaust valve seat recession in a natural gas fueled engine, the method comprising lubricating a natural gas fueled engine in need of exhaust valve seat recession prevention or inhibition with a natural gas engine lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity; (b) one or more phosphorus-containing anti-wear additives comprising a primary zinc alkyldithiophosphate, (c) about 1 wt. % to about 8 wt. %, based on the total weight of the natural gas engine lubricating oil composition, of one or more ashless dispersants comprising a bissuccinimide, (d) about 0.5 wt. % to about 2.5 wt. %, based on the total weight of the natural gas engine lubricating oil composition, of one or more alkaline earth metal salts of an alkyl-substituted hydroxyaromatic carboxylic acid having a total base number of from about 100 to about 250, wherein the one or more alkaline earth metal salts of alkyl-substituted hydroxyaromatic carboxylic acid are one or more calcium salts of an alkyl-substituted hydroxybenzoic acid and (e) about 0.1 wt. % to about 5 wt. %, based on the total weight of the natural gas engine lubricating oil composition, of one or more antioxidants comprising a hindered phenol compound, wherein the natural gas engine lubricating oil composition contains no more than about 0.03 weight percent of phosphorus, based on the total weight of the natural gas engine lubricating oil composition, and further wherein the natural gas engine lubricating oil composition is substantially free of any alkali metal-containing detergents.