The invention provides a lubricating composition comprising an oil of lubricating viscosity, 0.1 wt % to 10 wt % of an overbased detergent, and 0.01 wt % to 5 wt % of a non-hydroxy terminated acylated polyalkylene oxide. The invention further relates to a method of lubricating a mechanical device (such as an internal combustion engine) with the lubricating composition. The invention further relates to the use of the non-hydroxy terminated acylated polyalkylene oxide to provide at least one of (i) improved sludge handling, (ii) reduced lead or copper corrosion, (iii) increased oxidation resistance, (iv) improved acid control, (v) reduced wear (such as cam wear or lifter wear), (vi) retention of total base number of the lubricant, and/or (vii) improved seal compatibility in an internal combustion engine.

A lubricant composition includes an oil of lubricating viscosity and a 4-hydroxybenzamide as a friction modifier. The lubricant composition has a kinematic viscosity at 100° C. of from 5 to 18 mm2/s.

The invention provides a lubricating composition containing an oil of lubricating viscosity, an ashless thiocarbamate compound having an optionally-substituted hydrocarbyl group on an S-atom and an optionally-substituted hydrocarbyl group on an N-atom, and a boron-containing compound. The invention further relates to a method of lubricating an internal combustion engine with the lubricating composition.

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.

A lubricating oil composition for internal combustion engines containing a base oil (A), a metal-based detergent (B) containing a calcium-based detergent (B1), a zinc dialkyldithiophosphate (C), and a molybdenum-containing compound (D), wherein a calcium atom-equivalent content of the calcium-based detergent (B1) is more than 100 ppm by mass and 600 ppm by mass or less, based on a total amount of the composition, a magnesium atom-equivalent content of a magnesium-based detergent (B2) is less than 200 ppm by mass, based on the total amount of the composition, a sodium atom-equivalent content of a sodium-based detergent (B3) is less than 200 ppm by mass, based on the total amount of the composition, a content ratio of phosphorus derived from the zinc dialkyldithiophosphate (C) to calcium derived from the calcium-based detergent (B1) [P/Ca] is 0.25 or more by mass, and a sulfated ash content is 0.7% by mass or less; and a method for producing the composition.

A lubricating oil composition, and a method of reducing LSPI events employing the lubricating oil composition, including a base oil of lubricating viscosity, and an additive composition including: one or more overbased calcium-containing detergent(s) sufficient to provide at least 500 ppmw of calcium, and a zirconium-containing nanoparticle(s) and/or one or more zirconium-containing compound(s) sufficient to provide greater than 0 ppmw to 6000 ppmw of zirconium, wherein the nanoparticles have a size of from 1 to 500 nm, as measured by Dynamic Light Scattering, an amount of one or more molybdenum-containing compound present in an amount sufficient to provide no greater than 100 ppmw of molybdenum, and wherein the additive composition has a weight ratio of ppmw of zirconium provided by the zirconium-containing nanoparticle(s) and/or the one or more zirconium-containing compound(s) to the ppmw of calcium provided by the one or more overbased-calcium-containing detergent(s) of greater than about 0.01 to less than 5.

The invention provides a lubricating composition comprising a low viscosity base oil and a synergistic mixture of a functionalized ethylene-α-olefin copolymer, a poly(meth)acrylate polymer, and a metal-free anti-wear agent. The invention also provides a method of lubricating an internal combustion engine using such a lubricating composition.

The invention addresses a problem of providing a lubricating oil composition for gas engines capable of suppressing viscosity increase while reducing a sulfated ash content and excellent in high-temperature detergency and base number retention. The lubricating oil composition is used for gas engines and contains a base oil (A), at least one ash-free additive (B) selected from an ash-free sulfur-based antioxidant (B1) and a hindered amine compound (B2), and a boronated imide-type dispersant (C), and satisfies the following requirements (X1) to (X3): Requirement (X1): the sulfated ash content is 0.2% by mass or less. Requirement (X2): the content of the ash-free additive (B) is 1.2% by mass or less based on the total amount of the lubricating oil composition, provided that in the case where the ash-free additive (B) contains the hindered amine compound (B2), the content of the hindered amine compound (B2) is less than 1.0% by mass based on the total amount of the lubricating oil composition. Requirement (X3): the content of the boron atom derived from the boronated imide-type dispersant (C) is 200 ppm by mass or more based on the total amount of the lubricating oil composition.

Provided is a lubricating oil composition comprising a base oil (A) containing a polyalkylene glycol (A1) and a polyol ester (A2), a phosphorus-based rust inhibitor (B), and an antioxidant (C) containing an amine-based antioxidant (C1). The lubricating oil composition exhibits a strong effect for suppressing sludge sedimentation even when used for an extended period of time in a high-temperature environment, and has excellent demulsibility and rust preventive properties, and therefore, can be suitably used in turbomachinery, compressors, hydraulic equipment, and machine tools.

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.