Lubricating oil compositons

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.

Description

[0001]This application claims the benefit of and priority to U.S. Provisional Application Ser. No. 62 / 690,577, filed Jun. 27, 2018.TECHNICAL FIELD[0002]The disclosed technology relates to lubricants for a natural gas engine with steel pistons.BACKGROUND OF THE DISCLOSURE[0003]Natural gas fueled engines are engines that use natural gas as a fuel source. Lubricating oils with high resistance to oxidation, nitration and viscosity increase are generally preferred for lubricating oils used in natural gas engines because of the conditions related to this type of engine.[0004]Natural gas has a higher specific heat content than liquid hydrocarbon fuels and therefore it will burn hotter than liquid hydrocarbon fuels under typical conditions. In addition, since it is already a gas, natural gas does not cool the intake air by evaporation as compared to liquid hydrocarbon fuel droplets. Furthermore, many natural gas fueled engines are run either at or near stoichiometric conditions, where less ...