A lubricating oil composition for an internal combustion engine, the composition including: a lubricating base oil comprising at least one mineral base oil or at least one synthetic base oil or any combination thereof, the lubricating base oil having a kinematic viscosity at 100 C. of 4.0 to 4.5 mm.sup.2/s and a NOACK evaporation loss at 250 C. of no more than 15 mass %; (A) a calcium-containing metallic detergent in an amount of no less than 1000 mass ppm and less than 2000 mass ppm in terms of calcium on the basis of the total mass of the composition; (B) a magnesium-containing metallic detergent in an amount of 100 to 1000 mass ppm in terms of magnesium on the basis of the total mass of the composition; and optionally (C) a viscosity index improver in an amount of less than 1 mass % on the basis of the total mass of the composition.

The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

The lubricating oil composition of the present invention contains, together with a base oil, a viscosity index improver (A) including a comb-shaped polymer (A1), a detergent dispersant (B) including an alkali metal borate (B1) and an organometallic compound (B2) containing a metal atom selected from an alkali metal atom and an alkaline earth metal atom, and a friction modifier (C) including a molybdenum-containing friction modifier, with the total content of an alkali metal atom and an alkaline earth metal atom being 2,000 mass ppm or less. The lubricating oil composition of the present invention has excellent detergency, fuel saving properties, and LSPI-preventing properties.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

A lubricating oil composition, a method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine, and a use of a lubricant composition to reduce LSPI events in such an engine. Preferably, the composition comprises a detergent package comprising a borated calcium detergent, wherein the detergent package provides a calcium content in the composition of at least 0.12 mass %, based on the total mass of the composition, and wherein the borated calcium detergent provides a boron content in the composition of at least 100 ppmm, based on the total mass of the composition. Optionally, the composition comprises a first detergent comprising a calcium detergent, and a second detergent comprising a borated calcium detergent.

A lubricant composition is provided containing an oil of lubricating viscosity and a substantially sulfur-free alkyl phosphate amine salt, where at least 30 mole percent of the phosphorus atoms are in an alkyl pyrophosphate salt structure, along with either or both of a conventional phosphorous containing antiwear additive and a glycerol ester. In the phosphate amine salt, at least 80 mole percent of the alkyl groups are typically secondary alkyl groups of 3 to 12 carbon atoms. A method of improving wear over a wide temperature range in a mechanical device is also provided by employing the lubricant composition.

A lubricant composition is provided containing an oil of lubricating viscosity and a substantially sulfur-free alkyl phosphate amine salt, where at least 30 mole percent of the phosphorus atoms are in an alkyl pyrophosphate salt structure, along with either or both of a conventional phosphorous containing antiwear additive and a glycerol ester. In the phosphate amine salt, at least 80 mole percent of the alkyl groups are typically secondary alkyl groups of 3 to 12 carbon atoms. A method of improving wear over a wide temperature range in a mechanical device is also provided by employing the lubricant composition.

To provide a friction-reducing agent containing no sulfur nor phosphorus and being excellent in friction-reducing properties, and a lubricating oil composition using it. An alkanolamine represented by the following formula is used as a friction-reducing agent:

##STR00001##

wherein A.sub.1 and A.sub.2 are each independently a hydroxy group or a hydrogen atom, provided that A.sub.1 and A.sub.2 are not hydrogen atoms at the same time, R.sub.1 is a hydrocarbon group having at most 30 carbon atoms, R.sub.2 to R.sub.6 are each independently a hydrogen atom or a hydrocarbon group having at most 30 carbon atoms, and m and n are each independently an integer of from 0 to 10.

To provide a friction-reducing agent containing no sulfur nor phosphorus and being excellent in friction-reducing properties, and a lubricating oil composition using it. An alkanolamine represented by the following formula is used as a friction-reducing agent:

##STR00001##

wherein A.sub.1 and A.sub.2 are each independently a hydroxy group or a hydrogen atom, provided that A.sub.1 and A.sub.2 are not hydrogen atoms at the same time, R.sub.1 is a hydrocarbon group having at most 30 carbon atoms, R.sub.2 to R.sub.6 are each independently a hydrogen atom or a hydrocarbon group having at most 30 carbon atoms, and m and n are each independently an integer of from 0 to 10.

The present invention generally relates to compositions for use in lubricating oils. In certain aspects, the present invention is generally directed to boroxine compounds having alkyl groups where one or more of the alkyl groups contains at least 8 carbon atoms. Such compounds may present improved hydrolytic stability, compared to other boroxine compounds. Such boroxine compounds may be used, for example, to improve seal compatibility in an engine. Other aspects of the invention are generally directed to systems and methods for making such boroxine compounds, engine oils containing such boroxine compounds, methods of using such boroxine compounds, or the like.