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 disclosure provides a lubricant composition for lubricating an engine, a method for operating an engine and an additive concentrate. The lubricant composition includes a base oil of lubricating viscosity; one or more metal dialkyldithiophosphates having more than 75 mole percent of alkyl groups derived from 4-methyl-2-pentanol, and from about 0.1 to about 2.0 percent by weight of detergent derived from an alkyl phenol or sulfurized alkyl phenol based on a total weight of the lubricant composition. An amount of the one or more metal dialkyldithiophosphate in the lubricant composition ranges from about 0.01 to about 0.10 percent by weight phosphorus based on a total weight of the lubricant composition. The lubricant composition has a total a total base number (TBN) of about 5.0 to about 10.0.

The disclosed technology provides lubricating composition comprising: an oil of lubricating viscosity, a p-dodecyl-phenol-free detergent and an oxyalkylated hydrocarbyl phenol, wherein the oxyalkylated hydrocarbyl phenol is substituted with at least one aliphatic hydrocarbyl group of 1 to 250 carbon atoms (or 20 to 220, or 30 to 150 carbon atoms), and wherein the oxyalkylated hydrocarbyl phenol is substantially free of aromatic hydrocarbyl groups. 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 of the lubricating composition in a passenger car internal combustion engine to improve control of at least one of the following (i) fuel economy, (ii) corrosion, (iii) cleanliness, and (iv) bore wear.

Use of a guanidinium-based ionic liquid as detergent in a lubricant composition, notably for lubricating marine engines. A lubricant composition including a guanidinium-based ionic liquid.

Provided is a lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.7 to about 3.2 mPa s and a low temperature cold cranking viscosity of less than 7,000 mPa s at −20° C., comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. of from 3.5 mm.sup.2/s to 20 mm.sup.2/s and a viscosity index of greater than 120 with a sulfur content of less than 0.03 wt. %, are classified into the API group III, IV, or V base stock category, and have an aromatics content (C.sub.A) of less than 5%; (b) an organomolybdenum compound; (c) a dispersed hydrated alkali metal borate compound; (e) one or more dispersants; (f) one or more calcium-based metal detergents; and (g) optionally, one or more magnesium-based metal detergents. Also provided is a method for improving wear, high temperature detergency, and thermal stability in an engine comprising operating said engine with said lubricating oil composition.

The present invention relates to a lubricating oil composition containing a base oil (A), a molybdenum dithiocarbamate (B), an ester-based ashless friction modifier (C), and a metal salicylate (D), wherein the content of a molybdenum atom derived from the molybdenum dithiocarbamate (B) is 650 ppm by mass or more on the basis of the whole amount of the lubricating oil composition; a content ratio [C/B.sub.Mo] of the ester-based ashless friction modifier (C) to a molybdenum atom derived from the molybdenum dithiocarbamate (B) is 5.0 to 10 in terms of a mass ratio; the content of a salicylate soap group derived from the metal salicylate (D) is 0.50% by mass or more on the basis of the whole amount of the lubricating oil composition; and a kinematic viscosity at 100° C. is 4.0 mm.sup.2/s or more and less than 9.3 mm.sup.2/s, and a high-temperature high-shear viscosity at 150° C. is 1.7 mPa.Math.s or more and less than 2.9 mPa.Math.s. In accordance with the present invention, a viscosity-reduced lubricating oil composition in which nonetheless a molybdenum dithiocarbamate and an ashless friction modifier are jointly used, not only friction can be reduced early after commencement of lubrication, but also such a state can be maintained, is provided.

A lubricating oil composition containing a base oil, an organic molybdenum compound, and a metallic detergent, wherein the metallic detergent contains calcium sulfonate, and the content of the calcium sulfonate in terms of calcium atoms is 0.12% by mass or more based on the mass of the composition, the content ratio of molybdenum atoms derived from the organic molybdenum compound to soap groups derived from the metallic detergent based on the lubricating oil composition, [Mo/soap groups], is 0.02 or more at a mass ratio, and the HTHS viscosity at 150° C. is 1.3 mPa.Math.s or more and less than 2.3 mPa.Math.s. The lubricating oil composition has low viscosity and excellent lubricity.

Lubricant compositions comprising (a) an oil of lubricating viscosity and (b) a phosphonate ester other than a zinc salt. The phosphonate ester may be the reaction product of (i) phosphonic acid or a monomeric ester thereof with (ii) a propanediol having hydroxy groups in both the 1 and 3 positions and one or more of the carbon atoms of the propyl units are substituted with one or more alkyl groups such that the total number of carbon atoms in the propanediol ranges from 4 to 12. The molar ratio of (i) to (ii) may be 0.9:1.1 to 1.1 to 0.9.

Disclosed is a method for reducing corrosion in a hybrid engine. The method includes the steps of lubricating a hybrid engine with a lubricating oil composition having a major amount of an oil of lubricating viscosity; a minor amount of a salicylate detergent derived from an isomerized normal alpha olefin; and a minor amount of a dispersant.

A lubricant additive concentrate containing (i) dispersant that is the polybutenyl succinimide reaction product of a polyamine and polybutenyl succinic anhydride (PIBSA) derived from polybutene having a number average molecular weight (M.sub.n) of from about 1300 to about 2500 daltons and a terminal vinylidene content of at least about 50% and maleic anhydride via an ene maleation process; (ii) overbased magnesium colloidal detergent having a total base number (TBN) of from about 300 to about 900 mg KOH/g; and (iii) organic friction modifier selected from hydroxyalkyl alkyl amines of C.sub.14 to C.sub.24 hydrocarbons, at least one hydroxyalkyl alkyl ether amines of C.sub.13 to C.sub.24 hydrocarbons, at least one alkyl ester amine derived from triethanol amine having a C.sub.13 to C.sub.24 hydrocarbyl substituent, at least one non-basic, fatty acid amide, or a mixture thereof; wherein the combined mass % of dispersant (i) and overbased magnesium colloidal detergent (ii) in said concentrate is from about 15 to about 50 mass %: the mass ratio of (i):(ii) is from about 1:1 to about 6:1; and the concentrate contains from about 2 to about 10 mass % of organic friction modifier (iii); the remainder of the concentrate being composed of base oil and additives other than dispersant (i), overbased magnesium colloidal detergent (ii) and organic friction modifier (iii).