Disclosed is a lubricating composition including a base oil, a surfactant system and a phase-change material, especially water. The lubricating composition according to the invention is used to lubricate engines, especially for a vehicle. It has improved thermal performances compared to lubricating compositions of prior art. It also reduces clogging of the engine parts.

The lubricating oil composition according to the present invention is one including a base oil, (A) a substituted hydroxy aromatic carboxylic acid ester derivative represented by at least one of the general formula (I) and the general formula (II), and (B) a heterocyclic compound represented by the general formula (III) or (IV) blended therein, wherein a phosphorus content is 0.06 mass % or less on the basis of a total amount of the composition, and a sulfated ash content is 1.2 mass % or less on the basis of a total amount of the composition. The lubricating oil composition is capable of maintaining high-temperature detergency and acid neutralizing properties, even when amounts of a phosphorus component-containing additive and a metallic detergent are reduced.

A method of reducing the incidence of deposits on the pistons of a 4-stroke marine diesel engine during operation of the engine when it is fuelled with a marine residual fuel meeting the ISO 8217 2017 fuel standard for marine residual fuels and having a sulphur content of more than 0.1% and less than 0.5% by mass. The method includes the step of lubricating the engine using a lubricating oil composition comprising: a) at least 50% by mass, based on the mass of the composition, of an oil of lubricating viscosity; (b) 5 to 25% by mass, based on the mass of the composition, of an oil-soluble or oil-dispersible alkali metal or alkaline earth metal salicylate detergent, or a mixture of two or more oil-soluble or oil-dispersible alkali metal or alkaline earth metal salicylate detergents; (c) 0.1 to 10% by mass, based on the mass of the composition of one or more oil-soluble or oil-dispersible ashless dispersants; and optionally, (d) 0.1 to 10% by mass, based on the mass of the composition of a polyalkylene-substituted succinic anhydride.

The disclosed technology provides a lubricating composition comprising an oil of lubricating viscosity and 0.01 wt % to 10 wt % of an oxyalkylated aromatic polyol compound, wherein the aromatic compound has at least one alkoxy group represented by −OR.sup.1 group, R.sup.1 is hydroxyalkyl, or a (poly)ether group, and either: at least one hydroxyl group, or at least one alkoxy group represented by —OR.sup.1 group, where R.sup.1 is alkyl, or a (poly)ether group, or at least one oxyalkyl group represented by —OR.sup.1, where R.sup.1 is hydroxyalkyl or a (poly)ether group. The disclosed technology further relates to a method of lubricating a mechanical device (such as an internal combustion engine) with the lubricating composition. The disclosed technology further relates to the use of the oxyalkylated aromatic polyol compound in the lubricating composition to a passenger car internal combustion engine at least one of (i) control of fuel economy, (ii) control of corrosion, (iii) cleanliness, and (iv) control of bore wear.

The present disclosure relates to a lubricating fluid for an electric motor system and a method of lubricating gears and cooling a motor in an electric motor system. In particular, the disclosed technology relates to a lubricating fluid, for use in electric motor vehicle, comprising an oil of lubricating viscosity and at least one phosphorylated dispersant exhibiting increased resistivity after aging.

A lubricating oil composition comprising greater than 50 wt.% of a base oil of lubricating viscosity, and either: a) an additive composition comprising: one or more zinc, dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of zinc (Zn) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TEN) of the one or more dispersants to the TEN of the lubricating oil composition is a multiplication factor Zn*TBNDisp of at least about 0.06; or b) an additive composition comprising: one or more zinc dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of phosphorus (P) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TBN) of the one or more dispersants to the TBN of the lubricating oil composition is a multiplication factor P*TBNDisp of at least about 0.051.

A lubricating oil detergent composition comprises an overbased calcium sulfonate and a low ash detergent, which low ash detergent is metal free and comprises the reaction product of an acidic organic compound such as an alkylated salicylic acid, a boron compound and an amine component.

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; 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.

Disclosed is a monophasic lubricating composition including a base oil, an oil chosen from the polyalkylene glycols (PAG) and a phase-change material, in particular water. The monophasic lubricating composition can be used, in particular, for lubricating a vehicle engine. It has improved thermal performance relative to the lubricant compositions of the prior art. It also helps reduce fouling of the engine parts.

A lubricating oil composition for internal combustion engines is disclosed. The composition exhibits a lower coefficient of friction and improved cleaning properties without causing a deterioration in thermal and oxidation stability.