| abstract |
(57) [Summary] [Problem] A power generation capacity 30 used under high temperature conditions A gas engine oil capable of maintaining the oxidation stability of a gas engine oil for cogeneration of 00 KW or less for a long period of time. SOLUTION: The base material is a mineral oil-based lubricating oil, a synthetic oil-based lubricating oil, or a mixed oil thereof, and (A) a base number of 300 to 500. mgKOH / g, viscosity at 100 ° C. 1000 mm 2 / S or less, fatty acids 0.1 to 20% by mass of overbased sulfurized alkaline earth metal phenate of 1 to 20% by mass, (B) 1 to 20% by mass of a bis-type high molecular weight alkenyl succinimide or a derivative thereof, and (C) 0.1 to 5% by mass of a zinc dialkyldithiophosphate represented by the general formula (1). Embedded image It contains 0.1 to 5% by mass of the polymer hindered phenol compound (D) together with the components (A) to (C). |