The use of berated dispersant, preferably in combination with polyalkylenyl succinic anhydrides, to stabilise an additive concentrate which includes a salicylate detergent and a nitrogen-free ashless organic friction modifier.

The use of polyalkylenyl succinic anhydrides to stabilize an additive concentrate which includes a salicylate detergent and a nitrogen-free ashless organic friction modifier.

The use of polyalkylenyl succinic anhydrides to stabilize an additive concentrate which includes a salicylate detergent and a nitrogen-free ashless organic friction modifier.

The invention provides a method of lubricating a compression-ignition internal combustion engine with a maximum laden mass over 2,700 kg comprising supplying to the engine a lubricating composition comprising: an oil of lubricating viscosity, a 300 TBN or higher alkaline earth metal sulphonate detergent having a metal ratio of 10 to 40, 0.1 wt % to 4 wt % of a borated polyisobutylene succinimide dispersant, wherein the polyisobutylene from which the borated polyisobutylene succinimide is derived has a number average molecular weight of 550 to 1150, and 0.1 wt % to 6 wt % of a polyisobutylene succinimide, wherein the polyisobutylene from which polyisobutylene succinimide is derived has a number average molecular weight of 1550 to 2500, 0 wt % to 0.2 wt % of a phenolic based detergent, wherein the total amount of soap delivered by the alkaline earth metal sulphonates (typically calcium sulphonate) is 0.4 to 1 wt % of the lubricating composition, and wherein the lubricating composition has a sulphated ash content of not more than 1.5 wt %.

The invention provides a method of lubricating a 2-stroke marine diesel cylinder liner with a lubricating composition having a total base number of 10 to 25 mg KOH/g. The invention further provides a lubricating composition for lubricating the 2-stroke marine diesel cylinder liner.

The invention provides a method of lubricating a 2-stroke marine diesel cylinder liner with a lubricating composition having a total base number of 10 to 25 mg KOH/g. The invention further provides a lubricating composition for lubricating the 2-stroke marine diesel cylinder liner.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition is formulated to be resistant to turbocharger deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test. The lubricating oil composition may also have a low NOACK volatility, as measured by the method of ASTM D-5800 at 250° C.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition is formulated to be resistant to turbocharger deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test. The lubricating oil composition may also have a low NOACK volatility, as measured by the method of ASTM D-5800 at 250° C.

The invention provides a lubricating composition containing (a) an oil of lubricating viscosity, (b) a phosphite having at least one hydrocarbyl group that has 4 or more carbon atoms, and (c) a compound derived from a hydroxy-carboxylic acid. The invention further relates to the use of the lubricating composition in an internal combustion engine.

A lubricating oil composition for a continuously variable transmission contains at a specific content: (A) a mineral oil or PAO having a sulfur content of 0.03 mass % or less and a kinematic viscosity at 100 degrees C. from 1.5 mm.sup.2/s to 3 mm.sup.2/s; (B) a mineral oil or PAO having a sulfur content of 0.03 mass % or less and a kinematic viscosity at 100 degrees C. from 5.5 mm.sup.2/s to 8 mm.sup.2/s; (C) PAO having a kinematic viscosity at 100 degrees C. from 30 mm.sup.2/s to 400 mm.sup.2/s; and (D) a polymethacrylate having a mass average molecular weight of 10000 to 40000, in which the total content of the components (C) and (D) is 19 mass % or more and the lubricating oil composition has a kinematic viscosity at 100 degrees C. from 5.5 mm.sup.2/s to 6.5 mm.sup.2/s and a kinematic viscosity at −20 degrees C. of 680 mm.sup.2/s or less.