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.

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.

The present disclosure provides a lubricating oil composition which is excellent in metal fatigue life, wear resistance and electrical insulating properties, even when the composition has a reduced viscosity. The lubricating oil composition according to the present disclosure comprises: (A) a lubricating base oil; (B) from 0.6 to 4.0% by weight, based on the total weight of the lubricating oil composition, of a polydiene having a number average molecular weight of from 500 to 3,000 and containing a functional group on at least one end thereof; and (C) at least one selected from a phosphorus-based anti-wear agent and a phosphorus-based extreme pressure agent, the at least one agent being contained in such an amount that the content of phosphorus is from 50 to 500 ppm by weight based on the total weight of the lubricating oil composition.

Disclosed herein is an overbased alkaline earth metal hydrocarbyl-substituted salicylate detergent comprising both carbonate and borate moieties and exhibiting the following characteristics: a basicity index of at least 3.8; a ratio of soap content to mass % boron is greater than 55 mmol/kg; a soap content of at least 330 mmol/kg; a TBN, measured according to ASTM D2896, of at least 220 mg KOH/g; and a mass ratio of borate to carbonate from 0.75 to 6.0, wherein the alkaline earth metal comprises calcium and/or magnesium, and the hydrocarbyl substitution comprises 9 to 30 carbon atoms. Methods of making the boron-containing salicylate detergent, specifically to be package-stable, are also disclosed, as well as package-stable lubricant additive package concentrates and lubricating oil compositions containing same.

Disclosed herein is an overbased alkaline earth metal hydrocarbyl-substituted salicylate detergent comprising both carbonate and borate moieties and exhibiting the following characteristics: a basicity index of at least 3.8; a ratio of soap content to mass % boron is greater than 55 mmol/kg; a soap content of at least 330 mmol/kg; a TBN, measured according to ASTM D2896, of at least 220 mg KOH/g; and a mass ratio of borate to carbonate from 0.75 to 6.0, wherein the alkaline earth metal comprises calcium and/or magnesium, and the hydrocarbyl substitution comprises 9 to 30 carbon atoms. Methods of making the boron-containing salicylate detergent, specifically to be package-stable, are also disclosed, as well as package-stable lubricant additive package concentrates and lubricating oil compositions containing same.

A lubricating oil composition for an internal combustion engine includes: (A) a lubricating base oil including at least one mineral oil-based base oil and having a kinematic viscosity at 100° C. of from 2.0 mm.sup.2/s or more and 4.3 mm.sup.2/s or less, and (B) a calcium borate-containing metallic detergent in an mount of 500 mass ppm or more and less than 1500 mass ppm in terms of calcium, based on a total amount of the composition. The composition has an evaporation loss by NOACK method (250° C., 1 h) of from 10 mass % or more and 40 mass % or less, and the composition has a viscosity index of from 140 or more and 350 or less. The lubricating oil composition is provided, wherein even in the case of using a highly evaporative base oil to make the viscosity low, the friction characteristic of the lubricating oil composition can be kept low.

A lubricating oil composition for an internal combustion engine includes: (A) a lubricating base oil including at least one mineral oil-based base oil and having a kinematic viscosity at 100° C. of from 2.0 mm.sup.2/s or more and 4.3 mm.sup.2/s or less, and (B) a calcium borate-containing metallic detergent in an mount of 500 mass ppm or more and less than 1500 mass ppm in terms of calcium, based on a total amount of the composition. The composition has an evaporation loss by NOACK method (250° C., 1 h) of from 10 mass % or more and 40 mass % or less, and the composition has a viscosity index of from 140 or more and 350 or less. The lubricating oil composition is provided, wherein even in the case of using a highly evaporative base oil to make the viscosity low, the friction characteristic of the lubricating oil composition can be kept low.

The disclosed technology relates to lubricants for compression ignition internal combustion engines, particularly those demonstrating at least one of improved seals performance, reduced deposit formation, and excellent durability. The present invention provides a low zinc lubricating composition comprising (a) an oil of lubricating viscosity, (b) a borated dispersant, and (c) a metal-free organo-phosphorus anti-wear additive, wherein the lubricating composition is substantially free of a metal containing sulfur coupled alkyl phenol compound. Further, the low zinc lubricating composition contains zinc in an amount less than 600 ppm by weight of the composition.

The disclosed technology relates to lubricants for compression ignition internal combustion engines, particularly those demonstrating at least one of improved seals performance, reduced deposit formation, and excellent durability. The present invention provides a low zinc lubricating composition comprising (a) an oil of lubricating viscosity, (b) a borated dispersant, and (c) a metal-free organo-phosphorus anti-wear additive, wherein the lubricating composition is substantially free of a metal containing sulfur coupled alkyl phenol compound. Further, the low zinc lubricating composition contains zinc in an amount less than 600 ppm by weight of the composition.

A lubricant composition of an oil of lubricating viscosity and a phosphite ester reaction product of a monomeric phosphorous acid or an ester thereof with a first alkylene diol having two hydroxy groups in a 1,4 or 1,5 or 1,6 relationship and a second, alkyl-substituted, diol being a substituted 1,3-propylene diol, exhibits good wear and frictional performance.