A lubricating oil composition for reducing low-speed pre-ignition events or improving oxidation in a spark-ignited direct injection engine is disclosed. The composition includes a detergent additive which comprises either: an oil-soluble sulfonate including both magnesium and calcium as cations; or an oil-soluble salicylate including both magnesium and calcium as cations.

A lubricating oil composition for reducing low-speed pre-ignition events or improving oxidation in a spark-ignited direct injection engine is disclosed. The composition includes a detergent additive which comprises either: an oil-soluble sulfonate including both magnesium and calcium as cations; or an oil-soluble salicylate including both magnesium and calcium as cations.

A method for lubricating an internal combustion engine, the method including: supplying a lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950° C.

A method for lubricating an internal combustion engine, the method including: supplying a lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950° C.

An overbased metal detergent grease comprising at least one of polyalkylene glycol and/or an acid having at least one of both a nitrogen and a sulfur atom. The grease has improved extreme pressure performance as measured by the Standard Test Method for Measurement of Extreme-Pressure Properties of Lubricating Grease (Four-Ball Method), ASTM D2596. Methods of making an overbased metal detergent grease comprising using at least one of polyalkylene glycol and/or an acid having at least one of both a nitrogen and a sulfur atom. Methods of lubricating mechanical components using the grease comprising contacting the mechanical component with the grease. Mechanical components can include gears, drivetrain elements, bearings, hinges, or combinations thereof.

An overbased metal detergent grease comprising at least one of polyalkylene glycol and/or an acid having at least one of both a nitrogen and a sulfur atom. The grease has improved extreme pressure performance as measured by the Standard Test Method for Measurement of Extreme-Pressure Properties of Lubricating Grease (Four-Ball Method), ASTM D2596. Methods of making an overbased metal detergent grease comprising using at least one of polyalkylene glycol and/or an acid having at least one of both a nitrogen and a sulfur atom. Methods of lubricating mechanical components using the grease comprising contacting the mechanical component with the grease. Mechanical components can include gears, drivetrain elements, bearings, hinges, or combinations thereof.

A metal-containing detergent, suitable for use as a lubricant additive, in the form of a concentrate in oil in which a basic metal-containing material is maintained in dispersion or solution in the oil by a gemini surfactant system comprising, or being derivable or derived from, a double bond-unsaturated carboxylic acid having 8 to 30 carbon atoms, the double bond or bonds of which being functionalized to carry polar groups across or on the double bond or bonds and the carboxylic acid group or groups thereof being functionalized to become an amide or ester group carrying at least one alkyl group having 4 to 20 carbon atoms.

A metal-containing detergent, suitable for use as a lubricant additive, in the form of a concentrate in oil in which a basic metal-containing material is maintained in dispersion or solution in the oil by a gemini surfactant system comprising, or being derivable or derived from, a double bond-unsaturated carboxylic acid having 8 to 30 carbon atoms, the double bond or bonds of which being functionalized to carry polar groups across or on the double bond or bonds and the carboxylic acid group or groups thereof being functionalized to become an amide or ester group carrying at least one alkyl group having 4 to 20 carbon atoms.

Provided is a lubricating oil composition having excellent detergency and LSPI preventing performance, and specifically a lubricating oil composition including a base oil, a calcium detergent, and a magnesium detergent and/or a sodium detergent, wherein the content of the calcium detergent as converted into a calcium atom and a mass ratio of a magnesium atom (Mg) contained in the magnesium detergent and/or a sodium atom (Na) contained in the sodium detergent to a calcium atom (Ca) [(Mg and/or Na)/Ca] fall within the specific ranges.

Provided is a lubricating oil composition having excellent detergency and LSPI preventing performance, and specifically a lubricating oil composition including a base oil, a calcium detergent, and a magnesium detergent and/or a sodium detergent, wherein the content of the calcium detergent as converted into a calcium atom and a mass ratio of a magnesium atom (Mg) contained in the magnesium detergent and/or a sodium atom (Na) contained in the sodium detergent to a calcium atom (Ca) [(Mg and/or Na)/Ca] fall within the specific ranges.