The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an ashless dispersant. The ashless dispersant may be selected from succinimide compounds prepared from aliphatic or aromatic amines.

Provided is an internal combustion engine lubricating oil composition having a major amount of an oil of lubricating viscosity; a combination of alkaline earth metal alkylhydroxybenzoate detergents; at least about 50 to about 500 ppm of boron from a boron containing detergent; a molybdenum containing compound in an amount to provide the lubricating oil composition from about 100 to about 1500 ppm molybdenum; a ZnDTP compound; where the composition comprises magnesium in an amount from about 100 to about 800 ppm, and calcium in an amount from about 500 to about 2000 ppm.

A lubricating oil composition including: a lubricating base oil; (A) a poly(meth)acrylate having a weight average molecular weight of no more than 50,000, in an amount of 2 to 10 mass %; (B) a phosphite ester of the general formula (1) in an amount of 0.01 to 0.06 mass % in terms of P; (C) a thiadiazole compound in an amount of 0.01 to 0.2 mass %; and (D) a Ca salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of Ca, wherein the lubricating oil composition has a kinematic viscosity at 40° C. of 4.0 to 20.0 mm.sup.2/s, and a kinematic viscosity at 100° C. of 1.8 to 5.2 mm.sup.2/s; and has a ratio [S]/[P] of 2.2 to 4.0, wherein the [S] represents a sulfur content, and the [P] represents a phosphorus content: ##STR00001##
wherein R.sup.1 and R.sup.2 are each independently a group having 5 to 20 carbons represented by the general formula (2); and ##STR00002##
wherein R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C2-17 linear chain hydrocarbon group.

A lubricating oil composition comprising greater than 50 wt. % of a base oil of lubricating viscosity; an amount of one or more ester(s) of a polyhydric alcohol; an amount of one or more boron-containing dispersant(s); wherein a ratio of the amount of the one or more ester(s) of a polyhydric alcohol in weight percent provided to the lubricating oil composition, to an amount of boron in weight percent provided by the one or more boron-containing dispersant(s), based on the total weight of the lubricating oil composition is less than 40. The lubricating oil composition has improved corrosion performance in an engine or other mechanical components lubricated with the lubricating oil.

The present disclosure relates to polysiloxanes, processes for preparing polysiloxanes, and hydraulic fluids comprising polysiloxanes. This disclosure also relates to hydraulic fluids comprising one or more polysiloxane compounds and diphosphonate compounds, and to the use of diphosphonate compounds in hydraulic fluids or as additives or components in various compositions, for example to provide fire retardant properties to a fluid or composition. This disclosure also relates to use of the compositions as hydraulic fluids, which may be used in various machines, vehicles and craft, including aircraft.

The disclosed technology provides a lubricating composition and a method of lubricating an internal combustion engine where the lubricating composition contains an oil of lubricating viscosity, one or more metal-containing, sulfur-free, alkyl-phenol based detergents, an alkaline earth metal sulfonate detergent, a polyisobutenyl succinimide dispersant, and a dispersant viscosity modifier having a number average molecular weight of at least 20,000.

The lubricating composition of the present invention can be formulated to have lower HTHS viscosity, and reduced phosphorous content, while providing protection against adhesive wear.

Lubricating compositions for motor vehicles are disclosed. The lubricating composition is of grade according to the SAE J300 classification defined by the formula (X)W(Y), wherein X represents 0 or 5; and Y represents an integer ranging from 4 to 20; and comprises at least one diester of formula R.sup.a—C(O)—O—([C(R).sub.2].sub.n—O).sub.s—C(O)—R.sup.b (I). The composition may be used as a lubricant for an engine, in particular a vehicle engine, to reduce the fuel consumption of the engine and to improve engine cleanliness.

A lubricating composition includes an oil of lubricating viscosity, an N-alkyl naphthylamine, and at least one ashless antioxidant selected from a diarylamine antioxidant, a phenolic antioxidant, and mixtures thereof. The lubricating composition has a phosphorus content of less than 0.15 weight percent. The combination of the N-alkyl naphthylamine and ashless antioxidant provides a beneficial effect on the basicity of the composition without negatively impacting seals performance.

A C.sub.31 renewable base oil is disclosed that is suitable as a base oil to provide low viscosity base oils, such as having both low Noack volatility and low CCS-30° C. viscosity and/or to provide low viscosity base oils at the same time having a combination of acceptable HTHS and KV100 to allow the industry's base oil blenders to formulate high quality engine oils, such as SAE grade 0W-20, 0W-16, 0W-12 or 0W-8.

The disclosed technology provides a lubricating composition and a method of lubricating an internal combustion engine where the lubricating composition contains an oil of lubricating viscosity, one or more metal-containing, sulfur-free, alkyl-phenol based detergents, an alkaline earth metal sulfonate detergent, a polyisobutenyl succinimide dispersant, and a dispersant viscosity modifier having a number average molecular weight of at least 20,000. The lubricating composition of the present invention can be formulated to have lower HTHS viscosity, and reduced phosphorous content, while providing protection against adhesive wear.