A comb copolymer viscosity modifier may be made by polymerization comprising at least, or consisting essentially of, the following monomers: (a) (optionally from 7.0 wt % to 18 wt %, by repeat units, of) a hydrogenated polybutadiene-based (alk)acrylate ester macromonomer; (b) (optionally from 33 wt % to 64 wt %, by repeat units, of) a C.sub.3-C.sub.8alkyl (alk)acrylate ester monomer; (c) a C.sub.12-C.sub.24 alkyl (alk)acrylate ester monomer; and (d) (optionally from 3.0 wt % to 25 wt %, by repeat units, of) H-endcapped, C.sub.1-C.sub.18 alkyl-endcapped, or C.sub.6-C.sub.20 aryl-, aralkyl-, or alkaryl-endcapped C.sub.2-C.sub.6 oxyalkyl or C.sub.2-C.sub.6 oligo(alkylene glycol)-based (alk)acrylate ester monomer, wherein repeat units based on monomer (c) and/or monomer (d) comprise at least 21.0 wt % (and optionally up to 35.0 wt %) of repeat units of the comb copolymer viscosity modifier. Lubricant compositions comprising the comb copolymer viscosity modifier, as well as uses thereof and methods for modifying viscosity and dispersancy, are also contemplated.

The disclosed technology relates to a lubricant composition for automotive gears, axles and bearings, the lubricant composition containing an oil of lubricating viscosity and a metal thiophosphate compound, such as zinc dialkyldithiophosphate, as well as a method of obtaining extreme pressure performance in automotive gears, axles and bearings at lower sulfur content than is typical, by lubricating such automotive gears, axles and bearings with a lubricant composition containing a metal thiophosphate compound, such as zinc dialkyldithiophosphate.

A grease composition may be used for speed reducers and speed increasers, being excellent in both torque transmission efficiency and leak prevention performance. The grease composition may contain a base oil (A) and a urea-based thickener (B), which is used for speed reducers and speed increasers, wherein the particles containing the urea-based thickener (B) in the grease composition satisfy the following requirement (I). Requirement (I): the area-based arithmetic average particle diameter of the particles is 2.0 μm or less, as measured by a laser diffraction/scattering method.

The present disclosure relates to a lubricating fluid for an electric motor system and a method of lubricating gears and cooling a motor in an electric motor system. In particular, the disclosed technology relates to a lubricating fluid, for use in electric motor vehicle, comprising an oil of lubricating viscosity and at least one phosphorylated dispersant exhibiting increased resistivity after aging.

The instant disclosure generally relates to lubricating compositions having an oil of lubricating viscosity, a mixture of boron-containing and boron-free dispersants, an overbased magnesium-based detergent, an overbased calcium-based detergent, a molybdenum-containing material, and, optionally, other performance additives. The instant lubricating compositions may improve one or more of cleanliness, TBN retention, fuel economy and low-speed preignition (LSPI).

A composition for cleaning a combustion engine system. The composition comprises a hydrocarbon. The hydrocarbon comprises respective first and second hydrocarbons. The first hydrocarbon comprises a lubricant, wherein the lubricant has a flash point, measured according to ASTM D93, of less than 80 C. The second hydrocarbon comprises an aromatic hydrocarbon, wherein the aromatic hydrocarbon has a flash point, measured according to ASTM D93, of greater than 62 C. The composition further comprises an oxygen donor. The oxygen donor comprises respective first and second oxygen donors. The first oxygen donor comprises a hydroxyl group and has a flash point, measured according to ASTM D93, of from 45 C. to 95 C. The second oxygen donor comprises a carbonyl group or an ether group and has a flash point, measured according to ASTM D93, of from 50 C. to 120 C.

Disclosed are solvency enhancer compositions, for example, as additives to lubricating oils and as formulated in lubricating oil compositions and associated methods of preparation and use thereof. The compositions and methods can dissolve at least one of oxidation products and other organic polar compounds, due to lubricant degradation, formed and suspended in oil compositions including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols. Further described are methods for dissolving organic deposits in an oil system including adding an effective amount of a solvency enhancer to the oil system, wherein the solvency enhancer includes Guerbet alcohols. Also provided are methods for preventing sludge and varnish formation in in-service oils including adding an effective amount of a solvency enhancer to the oils, wherein the solvency enhancer includes Guerbet alcohols.

A dispersant composition is described. The composition includes a succinimide dispersant composition comprising a reaction product of a hydrocarbyl succinimide and a heteroaromatic glycidyl ether having a structure: ##STR00001## wherein R.sub.1 is a heteroaryl or heteroarylalkyl group having 4 to 20 carbon atoms, and R.sub.2 and R.sub.3 are independently a hydrogen atom, an alkyl group, or an aryl group.

A lubricating oil composition including: a lubricating base oil; (A) a poly(meth)acrylate having a weight average molecular weight of no more than 50,000, in an amount of 2 to 10 mass %; (B) a phosphite ester of the general formula (1) in an amount of 0.01 to 0.06 mass % in terms of P; (C) a thiadiazole compound in an amount of 0.01 to 0.2 mass %; and (D) a Ca salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of Ca, wherein the lubricating oil composition has a kinematic viscosity at 40? C. of 4.0 to 20.0 mm.sup.2/s, and a kinematic viscosity at 100? C. of 1.8 to 5.2 mm.sup.2/s; and has a ratio [S]/[P] of 2.2 to 4.0, wherein the [S] represents a sulfur content, and the [P] represents a phosphorus content: ##STR00001##
wherein R.sup.1 and R.sup.2 are each independently a group having 5 to 20 carbons represented by the general formula (2); and ##STR00002##
wherein R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C2-17 linear chain hydrocarbon group.

A lubricant composition includes (a) a hydrocarbon oil including at least 30% wt of isoparaffins, based on the total weight of the hydrocarbon oil, and (b) an alkoxylated natural oil. A method of using the lubricant composition in a water-based composition, in particular a water-based mud, to improve the lubricity and/or to reduce the foaming properties of the water-based composition is also disclosed.