The instant disclosure is directed to a method of lubricating a sump-lubricated, high efficiency, gasoline-fueled internal combustion engine. Said method involves supplying to the engine a lubricating composition comprising an oil of lubricating viscosity, an anti-wear agent, an ashless antioxidant, a metal-containing detergent, an ashless polyolefin dispersant, and (f) a polymeric viscosity modifier. The disclosure further provides a method of operating a high efficiency sump-lubricated gasoline-fueled internal combustion engine while maintaining or improving at least one of durability, deposit control, oxidation control, fuel economy, and resistance to knock and stochastic pre-ignition.

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.

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.

A lubricant formulation for an electric or hybrid vehicle includes a base oil, or a blend thereof, one or more additives, and a molybdenum amine complex, such as diisotridecylamine molybdate, are provided. Lubricant formulations can be characterized by one of: improving electric motor protection when a volatage is applied to an electrode in the presence of a formulation comprising the diisotridecylamine molybdate additive as compared to a fluid lacking the diisotridecylamine molybdate additive; maintaining the electrical resistance slope of a formulation comprising the diisotridecylamine molybdate additive as compared to a fluid lacking the diisotridecylamine molybdate additive; the formulation forming a protective film on copper surfaces; a change in color of the formulation indicating contact load, temperature, time, or viscosity change.

A lubricating composition suited to use for lubricating a hydraulic system includes an oil of lubricating viscosity and a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or metal salt thereof, wherein the wherein the polyolefin is derived from a isobutylene having a number average molecular weight of 150 to 800.

A lubricating composition includes a sulfurized oxy-substituted aromatic polyol compound and an oil of lubricating viscosity. The sulfurized oxy-substituted aromatic polyol compound includes at least one of a sulfurized oxy-substituted aromatic polyol and a salt of a sulfurized oxy-substituted aromatic polyol. The compound is suitable as a replacement for detergents that contain C.sub.n alkyl phenols derived from oligomers of propylene.

A lubricating composition includes a sulfurized oxy-substituted aromatic polyol compound and an oil of lubricating viscosity. The sulfurized oxy-substituted aromatic polyol compound includes at least one of a sulfurized oxy-substituted aromatic polyol and a salt of a sulfurized oxy-substituted aromatic polyol. The compound is suitable as a replacement for detergents that contain C.sub.n alkyl phenols derived from oligomers of propylene.

The present application relates to the use, in a lubricant composition comprising at least one base oil, of 2 to 12% by weight, relative to the weight of said lubricant composition, of an ester that has a viscosity at 100 C. of between 200 and 1000 cSt, for the purpose of improving the cleanliness of an engine.

This disclosure relates to grease compositions having at least one base oil, at least one soap or non-soap thickener, and at least one elastomeric triblock copolymer of the general configuration A-B-A, in which A is a relatively hydrophobic polymer block and B is a relatively hydrophilic polymer block, and in which A forms less than 50% by weight of the total molecular weight of the elastomeric triblock copolymer. When the grease compositions are used under high shear conditions, structural stability and resistance to breaking down in accordance with ASTM D7342 is improved. When the grease compositions are used in low temperature conditions, low temperature starting and running torque in accordance with ASTM D1478 is improved.

This disclosure relates to grease compositions having at least one base oil, at least one soap or non-soap thickener, and at least one elastomeric triblock copolymer of the general configuration A-B-A, in which A is a relatively hydrophobic polymer block and B is a relatively hydrophilic polymer block, and in which A forms less than 50% by weight of the total molecular weight of the elastomeric triblock copolymer. When the grease compositions are used under high shear conditions, structural stability and resistance to breaking down in accordance with ASTM D7342 is improved. When the grease compositions are used in low temperature conditions, low temperature starting and running torque in accordance with ASTM D1478 is improved.