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.

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 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.

Disclosed is a lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. in a range of about 2 to about 50 mm.sup.2/s; (b) a hydrocarbyl succinimide dispersant; (c) a borated hydrocarbyl succinimide dispersant; and (d) a hydrocarbyl succinimide post-treated with a post-treating agent selected from the group consisting of an organic carbonate, an epoxide, a lactone, a hydroxyaliphatic carboxylic acid, and combinations thereof.

The present disclosure relates to methods for improving phosphorus retention and improving antiwear performance in an internal combustion engine of a hybrid vehicle, comprising lubricating the internal combustion engine of the hybrid vehicle with a lubricating oil composition comprising: greater than 50 wt. % of a base oil of lubricating viscosity; and an amount of one or more zinc dialkyl dithiophosphate compound(s) sufficient to provide: from about 100 ppmw phosphorus to about 1000 ppmw phosphorus, based on a total weight of the lubricating oil composition; and from about 10 ppmw zinc to about 1200 ppmw zinc, based on the total weight of the lubricating oil composition.

The present disclosure relates to methods for improving phosphorus retention and improving antiwear performance in an internal combustion engine of a hybrid vehicle, comprising lubricating the internal combustion engine of the hybrid vehicle with a lubricating oil composition comprising: greater than 50 wt. % of a base oil of lubricating viscosity; and an amount of one or more zinc dialkyl dithiophosphate compound(s) sufficient to provide: from about 100 ppmw phosphorus to about 1000 ppmw phosphorus, based on a total weight of the lubricating oil composition; and from about 10 ppmw zinc to about 1200 ppmw zinc, based on the total weight of the lubricating oil composition.

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a boron-containing additive, a boron-free dispersant, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 of less than 2.7 mPa s. The instant lubricating compositions disclosed herein may accomplish one or more of the following improve fuel economy, reduce corrosion, reduce oxidation, improve cleanliness, and improve wear performance of an internal combustion engine.

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a boron-containing additive, a boron-free dispersant, an overbased magnesium-based detergent, an overbased calcium-based detergent, an ashless friction modifier, and, optionally, other performance additives. The instant lubricating composition has a High Temperature High Shear (HTHS) viscosity according to ASTM D4683 of less than 2.7 mPa s. The instant lubricating compositions disclosed herein may accomplish one or more of the following improve fuel economy, reduce corrosion, reduce oxidation, improve cleanliness, and improve wear performance of an internal combustion engine.