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.

A cylinder lubricating oil composition for a crosshead diesel engine equipped with a scrubber, including: a base oil; and (A) a metallic detergent, wherein the composition has a base number of 15 to 125 mgKOH/g, and a kinematic viscosity at 100° C. of 10 to 30 mm.sup.2/s; and the composition satisfies the requirement (i) or (ii): (i) the composition includes: (B) 0.02 to 5.0 mass % of a demulsifier; (ii) the composition includes, as the component (A), (A1) a Ca phenate detergent; and (A2) a metallic detergent other than Ca phenate; the composition optionally includes (C-1′) 0.015 mass % or less in terms of nitrogen of a succinimide dispersant or a borated derivative thereof; and the Ph value of the formula (1) is 20×10.sup.−3 or less:

Ph value=C.sub.Ca×2/(r.sub.M×40.08)  (1)

wherein C.sub.Ca represents calcium content (mass %) derived from the component (A1), and r.sub.M represents a metal ratio of the component (A1).

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.

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.

A lubricant composition of an oil of lubricating viscosity; an esterified copolymer with a backbone comprising units derived from (i) an α-olefin monomer of at least about 6 carbon atoms and (ii) an ethylenically unsaturated carboxylic acid in a mole ratio of 1:3 to 3:1; and a polymer comprising olefin monomer units of 3 to 5 carbon atoms, wherein at least 50 percent by weight of such units contain fewer than 6 carbon atoms and wherein less than 5 percent by weight of such units are ethylene monomer units; exhibits good power transfer efficiency and elastohydrodynamic film thickness.

A lubricant composition comprises an anti-wear and or/friction modifying additive which is an ester of a fatty acid and a polyol. At least 50% by weight of the additive is in the form of a mono-ester, and is preferably a mono-glyceride. The lubricant composition may be used in an internal combustion engine.

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 comprising at least 50 percent by mass, based on the mass of the composition of an oil of lubricating viscosity and 0.01 to 25 percent by mass, based on the mass of the composition of a polymer comprising units (a) and one or both units (b) and (c):
—N(COR.sup.1)(CH.sub.2).sub.x—  (a)
—NH(CH.sub.2).sub.y—  (b)
—N(CH.sub.2CH.sub.2-k(CH.sub.3).sub.kCOOR.sup.2)(CH.sub.2).sub.z   (c) where the total number (n) of units (a), (b) and (c) is an integer between 4 and 500; wherein x, y and z are independently 2 or 3; wherein k is zero or 1. The polymer shows good solubility in the lubricating oil and provides friction modification. A method of synthesising a polymer is also disclosed.

An oil composition comprises at least 50 percent by mass, based on the mass of the composition, of an oil and 0.01 to 25 percent by mass, based on the mass of the composition, of a polymer comprising at least one poly(lactone) segment. The at least one poly(lactone) segment is derived from a lactone substituted by one or two hydrocarbyl groups, or substituted hydrocarbyl groups, at least one such group having at least 4 carbon atoms. The oil compositions are suitable for use in the lubrication of the crankcase of internal combustion engines.

An industrial base oil formulation comprising a base oil, preferably a hydrocarbon base oil, having a kinematic viscosity of more than 100 centiStokes, preferably 150 centiStokes or more, at 40 degrees Celsius and an AC-OSP where the AC-OSP has the structure of Formula I: R.sup.1[O(R.sup.2O).sub.n(R.sup.3O).sub.mR.sup.4].sub.p (I) where R.sup.1 is an alkyl having from one to thirty carbons, R.sup.2 and R.sup.3 are independently selected from alkyl groups having three or four carbons and can be in block form or randomly combined, R.sup.4 is an alkyl having from one to 18 carbon atoms, n and m are independently numbers ranging from zero to 20 provided that n+m is greater than zero and p is a number within a range of one to three; wherein the industrial base oil formulation has a kinematic viscosity of greater than 100 centiStokes, preferably 150 centiStokes or more, at 40 degrees Celsius is useful in a lubricant for mechanical devices.