The present invention relates to a lubricating composition containing (a) an oil of lubricating viscosity; and (b) a compound selected from the group consisting of: (i) an ester-containing heterocycle; (ii) an amide-containing heterocycle; and (iii) a pyrimidine, wherein the ester-containing heterocycle and the amide-containing heterocycle have a hydrocarbyl group containing 6 to 40 carbon atoms. The invention further provides for a method of supplying an internal combustion engine with the lubricating composition.

A method of using lubricant compositions to reduce wear between two surfaces exposed to a load condition of at least 1 GPa is provided. The lubricant compositions comprise polysiloxane base oils having alkylaryl or a combination of alkyl and aryl functionality. The polysiloxane base oils may be defined according to the formula: ##STR00001##
wherein R, R, and R are independently selected, such that R is an alkyl group having between 1-3 carbon atoms; R is an alkylaryl group comprising alkyl functionality with 3-12 carbon atoms and aryl functionality with 6 to 12 carbon atoms; R is an alkyl group having between 1-3 carbon atoms or an alkylaryl group comprising alkyl functionality with 3-12 carbon atoms and aryl functionality with 6 to 12 carbon atoms; and m and n are integers, such that 8<(m+n)<500.

Lubricating oil compositions are provided which contain bimodal copolymer compositions, and in particular bimodal ethylene--olefin copolymer compositions. The copolymer compositions comprise first and second ethylene--olefin copolymer components. The bimodal compositions are particularly useful as viscosity or rheology modifiers, e.g., in lubricating oil compositions. Lubricating oil compositions comprising the copolymer compositions advantageously exhibit enhanced shear stability index (SSI) and thickening efficiency (TE) values, while maintaining excellent low-temperature properties such as pour point, mini-rotary viscometer viscosity, and cold crank simulation performance.

Lubricating oil compositions are provided which contain bimodal copolymer compositions, and in particular bimodal ethylene--olefin copolymer compositions. The copolymer compositions comprise first and second ethylene--olefin copolymer components. The bimodal compositions are particularly useful as viscosity or rheology modifiers, e.g., in lubricating oil compositions. Lubricating oil compositions comprising the copolymer compositions advantageously exhibit enhanced shear stability index (SSI) and thickening efficiency (TE) values, while maintaining excellent low-temperature properties such as pour point, mini-rotary viscometer viscosity, and cold crank simulation performance.

This disclosure relates to a liquid syndiotactic polyalphaolefin, sPAO, comprising one or more C.sub.4 to C.sub.24 monomers, said sPAO having: a) an rr triad content of 5 to 50% as measured by .sup.13C NMR; b) an mr triad content of 25 to 60% as measured by .sup.13C NMR, where the mr to mm triad ratio is at least 1.0; c) a pour point of Z C. or less, where Z=0.0648X51.2, where X=kinematic viscosity at 100 C. as reported in centistokes (cSt); d) a kinematic viscosity at 100 C. of 100 cSt or more (alternatively 200 cSt or more); e) a ratio of mr triads to rr triad (as determined by .sup.13C NMR) of less than 9; f) a ratio of vinylidene to 1,2-disubstituted olefins (as determined by .sup.1H NMR) of less than 8; g) a viscosity index of 120 or more; and h) an Mn of 40,000 or less. This disclosure further relates to processes to make and use sPAOs, including those having any combination of characterics a) to h).

A method for preparing a final grease product comprising steps of: (a) mixing a polymeric thickener, which comprises a polymer of propylene, and a lubricating base oil at a temperature above the melting point of the polymeric thickener, wherein the polymeric thickener is present in an amount of 11.5-15.5 wt %, based on the total weight of the mixture so obtained; (b) cooling the mixture as obtained in step (a); (c) subjecting the cooled mixture as obtained in step (b) to a first mechanical treatment, to obtain an intermediate grease; (d) subjecting the intermediate grease as obtained in step (c) to a second mechanical treatment, carried out at a temperature in the range of from 50-90 C., to obtain the final grease product. The method can be applied to manufacturing of a grease.

The lubricating oil composition of the invention comprises a lubricating base oil with a 100 C. kinematic viscosity of 1-20 mm.sup.2/s, (A) a friction modifier, (B) a first overbased metal salt obtained by overbasing an oil-soluble metal salt with an alkaline earth metal borate, and (C) an overbased second oil-soluble metal salt obtained by overbasing an oil-soluble metal salt with an alkaline earth metal carbonate.

The invention provides a method of lubricating an internal combustion engine equipped with a centrifugal oil mist separator, wherein the lubricant contains 0.1 wt % to 8 wt % soot resulting from operation of the engine, and wherein the lubricant composition comprises an oil of lubricating viscosity, and 0.2 wt % to 3 wt % of a soot dispersing additive having a shear stability index of 0 to 25, wherein the soot dispersing additive comprises a block copolymer comprising (i) a vinyl aromatic monomer block and (ii), a conjugated diene olefin monomer block.

The invention provides a method of lubricating an internal combustion engine equipped with a centrifugal oil mist separator, wherein the lubricant contains 0.1 wt % to 8 wt % soot resulting from operation of the engine, and wherein the lubricant composition comprises an oil of lubricating viscosity, and 0.2 wt % to 3 wt % of a soot dispersing additive, wherein the soot dispersing additive comprises a polymer chain having a number average molecular weight of 500 to 20,000, and wherein the soot dispersing additive has a shear stability index of 0 to 20.

The present invention is directed to a lubricating oil additive containing a vicinal diol and a particular detergent blend typically is low viscosity base oils whereby exhibiting improved fuel economy. In this respect, disclosed is a lubricating oil composition comprising: a major amount of base oil of lubricating viscosity; a friction modifier which is selected from the group consisting of C.sub.10-C.sub.30 alkane 1,2-diols and C.sub.10-C.sub.30 alkene 1,2-diols; an overbased alkyl alkaline earth metal hydroxybenzoate detergent having a metal ratio less than 3.0; and an overbased alkyl calcium sulfonate or an overbased alkyl calcium hydroxybenzoate having a metal ratio of 3.5 or greater.