Use of a liquid fuel composition in an internal combustion engine, the internal combustion engine containing a lubricating composition for lubricating said internal combustion engine, wherein the liquid fuel composition comprises at least one nitrogen-containing detergent additive, for the purpose of reducing engine wear caused by the presence of soot in the lubricating composition.

A lubricating composition comprising a base oil and one or more additives, wherein the composition has: a sulphated ash content (according to ASTM D 874) of at least 0.4 wt % and at most 1.0 wt. %, by weight of the lubricating composition; a total base number (TBN) value (according to ASTM D 2896) of at least 4.0 mg KOH/g and at most 12 mg KOH/g; a total aromatics content contributed by the base oil in the range from 1 wt % to 30 wt %, by weight of the lubricating composition; and a sulphur content contributed by the base oil of 0.4 wt % or less, by weight of the lubricating composition; and wherein the base oil comprises a blend of (i) a first base oil which is a mineral base oil selected from an API Group I mineral base oil and an API Group II mineral base oil, and mixtures thereof, and (ii) a second base oil selected from an API Group II base oil and an API Group III base oil, preferably wherein the first base oil belongs to a different API group to that of the second base oil.

Use of a gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the gasoline fuel composition comprises a gasoline base fuel and has a PM Index of 1.4 or less.

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.

New ashless TBN molecules are synthesized, and lubricant compositions containing them, boost the total base number. The lubricant compositions further tested for ASTM D6594 copper corrosion test meets ASTM limits.

A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100° C. of 9.3 to 11.0 mm.sup.2/s.

The present invention relates to the use of lubricant composition containing a base oil and at least one alkyl methacrylate polymer, to reduce engine particulate emissions.

A lubricating oil composition for an internal combustion engine includes: a lubricant base oil including at least one mineral base oil, at least one synthetic base oil, or any combination thereof, and having a kinematic viscosity at 100° C. of 3.0 to 4.0 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; (B) a magnesium-containing metallic detergent in an amount of 100 to 1000 mass ppm in terms of magnesium; (G) a zinc dialkyl dithiophosphate in an amount of no less than 600 mass ppm in terms of phosphorus; and optionally (C) a viscosity index improver in an amount of no more than 5 mass %.

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.

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.