Disclosed is a lubricating oil composition. The lubricating oil composition contains a lubricating base oil including mineral base oil, 4 to 15 mass % of an ester compound of a monovalent or polyvalent aliphatic carboxylic acid and a monovalent or polyvalent aliphatic alcohol, 400 to 1200 mass ppm of zinc dialkyl dithiophosphate in terms of a phosphorus element, 500 to 3000 mass ppm of a calcium-based detergent in terms of a calcium element, and 50 to 1000 mass ppm of a boron-modified succinimide-based dispersant in terms of a boron element, on the basis of the total amount of the lubricating oil composition.

Disclosed is a lubricating oil composition. The lubricating oil composition contains a lubricating base oil including mineral base oil, 4 to 15 mass % of an ester compound of a monovalent or polyvalent aliphatic carboxylic acid and a monovalent or polyvalent aliphatic alcohol, 400 to 1200 mass ppm of zinc dialkyl dithiophosphate in terms of a phosphorus element, 500 to 3000 mass ppm of a calcium-based detergent in terms of a calcium element, and 50 to 1000 mass ppm of a boron-modified succinimide-based dispersant in terms of a boron element, on the basis of the total amount of the lubricating oil composition.

Lubricating compositions comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. The lubricating composition also comprises an antiwear agent. Methods of lubricating an internal combustion engine comprise contacting the internal combustion engine with a lubricating composition comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. Methods of reducing lubricant oxidation and/or corrosion in an internal combustion engine with a lubricating composition comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative. The use of a comprising a thiol-carboxylic adduct that is the reaction product of a thiol and carboxylic acid and/or a carboxylic acid derivative to reduce lubricant oxidation and/or corrosion in an internal combustion engine.

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.

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 invention relates to the use of quaternized nitrogen compounds as a fuel and lubricant additive or kerosene additive, such as in particular as a detergent additive, for decreasing or preventing deposits in the injection systems of direct-injection diesel engines, in particular in common rail injection systems, for decreasing the fuel consumption of direct-injection diesel engines, in particular of diesel engines having common rail injection systems, and for minimizing the power loss in direct-injection diesel engines, in particular in diesel engines having common rail injection systems; the invention further relates to the use as an additive for petrol, in particular for operation of DISI engines.

Lubricating compositions comprising an azole-acrylic adduct formed by contacting an azole compound with an acrylic. The adduct formed has at least one N-alkyl group comprising at least one acyl. The lubricating composition also comprises a thiadiazole. Methods of lubricating a component of a farm tractor, off-highway vehicle or drivetrain comprising contacting the component with the lubricating composition comprising an azole-acrylic adduct formed by mixing an azole compound with an acrylic. Methods of reducing corrosion in a component. The use of an azole-acrylic adduct in a lubricating composition to reduce corrosion in a component.