Natural gas engine lubricating oil compositions
AssigneeChevron Oronite Company LLC
InventorsMelanie F. Tobias, Jon F. Von Staden
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Abstract
A natural gas engine lubricating oil composition is disclosed which comprises (a) a major amount of an oil of lubricating viscosity, (b) one or more phosphorus-containing anti-wear additives, (c) one or more oil soluble overbased alkaline earth metal-containing detergents; and (d) one or more oil soluble neutral alkali metal-containing detergents, 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.
Claims16
A natural gas engine lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity, (b) about 0.15 to about 1.5 wt. % of one or more phosphorus-containing anti-wear additives, wherein the one or more phosphorus-containing anti-wear additives comprises a zinc alkyldithiophosphate:
- (c) about 0.5 wt. % to about 1.5 wt. % of one or more oil soluble overbased alkaline earth metal-containing detergents comprising an oil soluble overbased calcium or magnesium phenate wherein the one or more oil soluble overbased alkaline earth metal-containing detergents have a base number (BN) of from greater than 50 to about 200;
- and (d) about 0.5 wt. % to about 2.0 wt. % of one or more oil soluble neutral alkali metal-containing detergents comprising an oil soluble neutral sodium or potassium sulfonate, 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 wherein said lubricating oil composition has a sulfated ash content of no more than about 1 wt. % as determined by ASTM D 874.
A method for preventing or inhibiting exhaust valve seat recession in a natural gas fueled engine, the method comprising lubricating the natural gas fueled engine with a natural gas engine lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity;
- (b) about 0.15 to about 1.5 wt. % of one or more phosphorus-containing anti-wear additives, wherein the one or more phosphorus-containing anti-wear additives comprises a zinc alkyldithiophosphate;
- (c) about 0.5 wt. % to about 1.5 wt. % of one or more oil soluble overbased alkaline earth metal-containing detergents comprising an oil soluble overbased calcium or magnesium phenate wherein the one or more oil soluble overbased alkaline earth metal-containing detergents have a base number (BN) of from greater than 50 to about 200;
- and (d) about 0.5 wt. % to about 2.0 wt, % of one or more oil soluble neutral alkali metal-containing detergents comprising an soluble neutral sodium or potassium sulfonate, 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 wherein said lubricating oil composition has a sulfated ash content of no more than about 1 wt. % as determined by ASTM D 874.
Dependencies are inferred from the claim text.