A lubricating oil composition including: a lubricant base oil; (A) a calcium salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of calcium on the basis of the total mass of the composition; and (B) a phosphite ester compound represented by the following general formula (1) in an amount of 0.01 to 0.06 mass % in terms of phosphorus on the basis of the total mass of the composition:

##STR00001##

wherein in the general formula (1), R.sup.1 and R.sup.2 are each independently a C5-20 group represented by the following general formula (2):

##STR00002##

wherein in the general formula (2), R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C3-17 linear chain hydrocarbon group, and X.sup.1 is an oxygen atom or a sulfur atom.

The invention relates to lubricating greases based on alkali metal soaps and/or earth-alkali metal soaps and metal complex soaps based on (R)-10-hydroxyoctadecanoic acid and to the use thereof.

Provided is a lubricating oil composition for a gas engine, comprising a base oil (A), a calcium-based detergent (B), and an alkenyl succinimide (C), wherein a content of calcium atoms is 0.09 to 0.17 mass % based on the total amount of the lubricating oil composition, the component (C) comprises a non-boron-modified alkenyl bis-succinimide (C1), and a content of boron atoms derived from the component (C) is less than 0.02 mass % based on the total amount of the lubricating oil composition.

A lubricating composition including a polymer blend of a modified styrene-maleic anhydride copolymer and poly(meth)acrylate copolymer effective to maintain a pumpable fluid at low temperatures.

The disclosed technology 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 sulfonate detergent having a metal ratio of 10 to 40, an alkaline earth metal sulfonate detergent having a metal ratio of 3 to 9, and a TBN of 81 to 180 mg KOH/g, wherein the sulfonate detergents provide a total amount of sulfonate substrate of 1 wt % to 3 wt % of the lubricating composition, 0.1 to 1.2 wt % of antioxidant, wherein at least 20 wt % of the antioxidant is a phenolic antioxidant, a borated compound present in an amount to deliver 25 ppm to 300 ppm of boron, the lubricating composition has a sulfated ash content of 0.5 wt % to not more than 1.5 wt %, and the lubricating composition has a TBN of 6.5 to 15 mg KOH/g.

A method of reducing low-speed pre-ignition (LSPI) in a direct-injected spark-ignited internal combustion engine comprising lubricating the crankcase of the engine with a composition comprising a combination of a molybdenum-containing additive and a boron-containing additive. Preferably, the composition comprises a calcium detergent providing a calcium content of at least 0.08 wt. %, based on the weight of the lubricating oil composition.

The invention concerns additive compositions obtained by mixing at least two thermoassociative and exchangeable compounds and at least one boronic ester compound that enables the association of these two copolymers to be controlled; a lubricating composition obtained by mixing at least one lubricating base oil, at least two thermoassociative and exchangeable compounds, and at least one boronic ester compound that enables the association of these two copolymers to be controlled; a method for adjusting the viscosity of a lubricating composition obtained by mixing at least one lubricating base oil and at least two thermoassociative and exchangeable compounds; and the use of a boronic ester compound to adjust the viscosity of a lubricating composition.

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 composition and method for improving engine performance using a renewable base oil composition comprising hydrocarbon mixtures and a lubricant additive having a sulfur content of up to about 0.4 wt. % and a sulphated ash content of up to about 0.5 wt. % is described herein.

Disclosed is a method for maintaining emulsion stability in a hybrid engine. The method involves lubricating and operating the hybrid engine with a lubricating oil composition having a major amount of an oil of lubricating viscosity; minor amount of a magnesium containing detergent, and a minor amount of a borated dispersant.