The present invention relates to a lubricating oil composition containing a base oil (A) and a viscosity index improver (B) such that in X-ray small-angle scattering spectra obtained through measurement at 40 C. and 100 C., a ratio [|(40)|/|(100)|] between |(40)| and |(100)|, each of which is an absolute value of a slope of a straight line calculated in a range of the scattering vector q as the x axis of from 0.1 nm .sup.1 to 1 nm .sup.by the least-squares method, is 1.5 or more.

In some embodiments, ethylene-propylene branched copolymers are synthesized with pyridyldiamido catalysts and a chain transfer agent, and their performance as viscosity modifiers in oil are detailed. In some embodiments, the present disclosure provides for ethylene-propylene branched copolymers having a shear thinning onset of less than about 0.01 rad/s and an HTHS value of less than about 3.3. In some embodiments, the ethylene-propylene branched copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

In some embodiments, ethylene-propylene branched copolymers are synthesized with pyridyldiamido catalysts and a chain transfer agent, and their performance as viscosity modifiers in oil are detailed. In some embodiments, the present disclosure provides for ethylene-propylene branched copolymers having a shear thinning onset of less than about 0.01 rad/s and an HTHS value of less than about 3.3. In some embodiments, the ethylene-propylene branched copolymer is used as a viscosity modifier in a lubricating composition and a fuel composition.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof: ##STR00001##
wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

The invention relates to low molecular weight hydrogenated polybutadienes and to a method for the preparation of these polymers. The invention is also directed to lubricant compositions comprising these polymers and uses thereof.

In the field of lubricating compositions for motor vehicles, there is disclosed a lubricating composition of a grade according to the SAEJ300 classification defined by the formula (X) W (Y) wherein X represents 0 or 5 and Y represents an integer ranging from 4 to 20. This lubricating composition includes at least one polyalphaolefinic oil (PAO), from 10 to 80% by weight of the composition of at least one oil of group V and at least one comb polymer. Also isclosed is the use of this lubricating composition for improving the Fuel Eco (FE) of a lubricant or for reducing the fuel consumption of an engine, in particular a motor vehicle engine, notably a motor of a hybrid vehicle.

The present disclosure provides a lubricating oil composition which has a viscosity much lower than that of a conventional lubricating oil composition, and which is excellent in metal fatigue life, wear resistance and electrical insulating properties. The lubricating oil composition according to the present disclosure comprises: (A) a lubricating base oil; and (B) from 0.6 to 4.0% by weight, based on the total weight of the lubricating oil composition, of a polydiene having a number average molecular weight of from 500 to 3,000 and containing a functional group on at least one end thereof. The above described lubricating oil composition does not comprise a viscosity index improver, and has a kinematic viscosity at 100 C. of not less than 1 and less than 5 mm.sup.2/s.

A lubricating oil composition having greater than 50 wt % of a base oil and 0.1 wt % to 20 wt %, both based on the total weight of the lubricating oil composition, of a dispersant viscosity modifier obtainable by: A) reacting: a) at least one of a lactone of formula (I) or a derivative thereof:

##STR00001##

wherein X is oxygen, and R is an optionally substituted hydrocarbylene group having from 1 to 20 carbon atoms; and b) at least one compound selected from amines, alcohols and oxazolines; and B) reacting the reaction product of step A) onto an acylated olefin copolymer obtainable by acylating a copolymer of ethylene and one or more C.sub.3-C.sub.10 alpha-olefins having a number average molecular weight of 5,000 to 200,000 g/mol as measured by GPC, with an acylating agent. Methods employing the lubricating oil compositions and uses of the lubricating compositions as engine oils are also described.

A lubricating composition including an oil of lubricating viscosity and a benzazepine compound. Methods of using such lubricating compositions are also disclosed.

Provided is a non-Newtonian engine oil lubricant composition with improved fuel efficiency and engine wear protection. The lubricant composition includes a major amount of a base oil including a Group II base stock and an optional Group V base stock, from 0.1 to 9.0 wt. % of at least one viscosity modifier and from 0.1 to 1.2 wt. % of at least one friction modifier. The non-Newtonian engine oil lubricant composition has a kinematic viscosity at 100 deg. C. of less than or equal to 10 cSt and an HTHS (ASTM D4683) of less than or equal to 2.2 cP at 150 C. Also provided are methods of using the lubricant composition in internal combustion engines and methods of making the lubricant composition.