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.

A lubricating oil composition is provided which comprises (a) greater than 50 wt. % of a base oil of lubricating viscosity; and (b) 0.1 to 40 wt. % of an overbased alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate, wherein the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 12 to 40 carbon atoms, and having a TBN, on an actives basis, of less than 600 mg KOH/g, as determined by ASTM D 2896; wherein the lubricating oil composition is a monograde lubricating oil composition meeting specifications for SAE J300 revised January 2015 requirements for a SAE 20, 30, 40, 50, or 60 monograde engine oil, and has a TBN of 5 to 200 mg KOH/g, as determined by ASTM D2896.

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.

A lubricating oil composition is provided which comprises (a) greater than 50 wt. % of a base oil of lubricating viscosity; and (b) 0.1 to 40 wt. % of an overbased alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate, wherein the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 12 to 40 carbon atoms, and having a TBN, on an actives basis, of less than 600 mg KOH/g, as determined by ASTM D 2896; wherein the lubricating oil composition is a monograde lubricating oil composition meeting specifications for SAE J300 revised January 2015 requirements for a SAE 20, 30, 40, 50, or 60 monograde engine oil, and has a TBN of 5 to 200 mg KOH/g, as determined by ASTM D2896.

A lubricant composition comprising an oil of lubricating viscosity and 0.01 to 5 percent by weight of a substantially sulfur-free alkyl phosphate amine salt, where at least 30 mole percent of the phosphorus atoms are in an alkyl pyrophosphate salt structure, exhibits good antiwear performance. In the phosphate amine salt, at least 80 mole percent of the alkyl groups are typically secondary alkyl groups of 3 to 12 carbon atoms.

A lubricating oil composition can include a major amount of an oil of lubricating viscosity and a minor amount of an alkaline earth metal phenol-based detergent. The lubricating oil composition can further have a BN of greater than 140 mg KOH/g, and further wherein the marine diesel cylinder lubricating oil composition is substantially free of unsulfurized tetrapropenyl phenol and its unsulfurized metal salt.

A method for lubricating an internal combustion engine, the method including: supplying a lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950° C.

A method for lubricating an internal combustion engine, the method including: supplying a lubricating oil composition to a cylinder of an internal combustion engine, wherein the internal combustion engine has a mean effective pressure of no less than 1.3 MPa, wherein an integrated intensity ratio of peaks of CaO in a X-ray diffraction spectrum of an ash is no more than 16.5%, the ash being obtained by incinerating the lubricating oil composition in an air at 950° C.

The present invention provides a lubricating oil composition for two-wheeled vehicles, which is able to not only suppress a lowering of fatigue life of engine parts while making fuel saving properties (in particular, fuel saving properties at the time of low speed) favorable but also make clutch friction characteristics of two-wheeled vehicles favorable. The present invention is concerned with a lubricating oil composition for two-wheeled vehicles, including a base oil (A) having a viscosity index of 120 or more, an ethylene-propylene copolymer (B), and a metal-based detergent (C), wherein the content of the ethylene-propylene copolymer (B) is 0.30% by mass or more on the basis of the whole amount of the lubricating oil composition; the metal-based detergent (C) contains a calcium phenate (C1) and a calcium sulfonate (C2), and a mass ratio of the content (Ca.sub.1) of the calcium phenate (C1) as expressed in terms of a calcium atom to the content (Ca.sub.2) of the calcium sulfonate (C2) as expressed in terms of a calcium atom is satisfied with a relation of (1.0≤Ca.sub.1/Ca.sub.2); and the lubricating oil composition has a kinematic viscosity at 100° C. is less than 9.3 mm.sup.2/s and an HTHS viscosity at 150° C. is 2.9 mPa.Math.s or more.

A method of lubricating at least a portion of a powertrain in a vehicle with an electric motor with a functional fluid composition containing greater than 50 wt % of a base oil; and an additive composition prepared by mixing: a) a hydrocarbyl acid phosphate of the formula (I) to provide at least 50 ppmw phosphorus to the functional fluid composition; ##STR00001##
wherein R is a C.sub.1-C.sub.6 hydrocarbyl group and R.sub.1 is selected from hydrogen and a C.sub.1-C.sub.6 hydrocarbyl group; b) an amount of one or more calcium-containing detergent(s) sufficient to provide at least 25 ppmw calcium to the functional fluid composition; and c) one or more nitrogen containing dispersants in an amount sufficient to provide greater than 20 ppmw of nitrogen to the functional fluid composition, all based on the total weight of the functional fluid composition. Functional fluid compositions containing the above-mentioned components and lubricating methods are also disclosed herein.