| abstract |
Disclosed is a natural gas engine lubricating oil composition which comprises: (a) a major amount of an oil of lubricating viscosity having a kinematic, (b) greater than about 2 wt. % but less than about 4 wt. %, based on the total weight of the natural gas engine lubricating oil composition, of one or more phenolic antioxidants, (c) about 0.1 to about 1 wt. %, based on the total weight of the natural gas engine lubricating oil composition, of one or more aminic antioxidants, (d) one or more metal dithiophosphates, and (e) one or more alkali metal or alkali earth metal phenate detergents having a TBN of about 150 to about 250 on an oil free basis, wherein the one or more alkali metal or alkali earth metal phenate detergents provide at least about 0.10 wt. % of alkali metal or alkali earth metal to the natural gas engine lubricating oil composition. |