A method for improving deposit control and cleanliness performance in an engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil comprises a lubricating oil base stock as a major component, and a mixture of (i) at least one dispersant, and (ii) at least one viscosity modifier, as minor components. The at least one dispersant and the at least one viscosity modifier are present in an amount sufficient to have a critical dispersant thickening ratio of greater than 0.33. The critical dispersant thickening ratio is determined in accordance with the formula:

[00001]$\frac{{\left[G_n\right]}^{*}.Math.\mathrm{dV}.Math.\text{/}.Math.d\left[G_n\right]}{{\left[B_m\right]}^{*}.Math.\mathrm{dV}.Math.\text{/}.Math.d\left[B_m\right]}$

wherein [G.sub.n] is the weight percent of each of n dispersants in the formulated oil, [B.sub.m] is the weight percent of each of m viscosity modifiers in the formulated oil, dV/d[G.sub.n] is the kinematic viscosity (Kv.sub.100) increase of the lubricating oil per the weight percent of each of n dispersants in the formulated oil, and dV/d[B.sub.m] is the kinematic viscosity (Kv.sub.100) increase of the lubricating oil per the weight percent of each of m viscosity modifiers in the formulated oil.

A lubricant composition includes a controlled release friction modifier (CRFM), a highly paraffinic base stock, a dispersant and a detergent. The CRFM includes an ionic tetrahedral borate compound including a cation and a tetrahedral borate anion, wherein the tetrahedral borate anion comprises a boron atom having two bidentate di-oxo ligands of C.sub.18 tartrimide. The lubricant composition can also include at least one of a Group V co-base stock, an inorganic friction modifier, a viscosity modifier, and a cleanliness booster.

A lubricant composition includes a controlled release friction modifier (CRFM), a highly paraffinic base stock, a dispersant and a detergent. The CRFM includes an ionic tetrahedral borate compound including a cation and a tetrahedral borate anion, wherein the tetrahedral borate anion comprises a boron atom having two bidentate di-oxo ligands of C.sub.18 tartrimide. The lubricant composition can also include at least one of a Group V co-base stock, an inorganic friction modifier, a viscosity modifier, and a cleanliness booster.

Disclosed herein are star-shaped macromolecular structures comprising a hyper-branched silicon containing core grafted with a well-defined and controllable number of alkyl (methyl)acrylate (co)polymer arms. The presence of the robust inorganic core provides additional resilience against mechanical degradation and therefore enhanced additive life time. Control over the additive architecture was complemented by tunability of the length of the grafted polymers by making use of controlled radical based polymerization techniques. The performance of these novel inorganic-organic star-shaped hybrids were compared to traditional fully organic lubricant additives. Detailed analysis revealed the multi-functional character of the hybrids by simultaneously performing as bulk viscosity modifiers, boundary lubricant, and wear protectants while being dispersed in a commercially available base oil for automotive lubrication purposes.

A lubricating oil composition containing a base oil (A), a comb-shaped polymer (B), and an olefin-based copolymer (C), wherein a content of the component (B) is more than 0.80 mass % based on the total amount of the lubricating oil composition, a weight average molecular weight of the component (C) is 500,000 or more, and the lubricating oil composition has a viscosity index of 200 or more and a kinematic viscosity at 100? C. of 9.3 to 11.0 mm.sup.2/s.

A composition is provided to comprise a non-aqueous medium and a 3,4-oxypyridinone compound of structure (I):

##STR00001##

with each A being oxygen and/or sulfur, and with a variety of substituents at R.sub.1-R.sub.5 to enable a solution or an at least semi-stable emulsion to be formed in the non-aqueous medium. Methods of use are included herein, which may be focused on situations where the composition can be used as a lubricant and/or coolant.

A viscosity index improver containing, in non-ester diluent oil, one or more hydrogenated, functionalized linear block copolymers having at least one block derived from monoalkenyl arene covalently linked to at least one block derived from diene in an amount that is greater than the critical overlap concentration (c.sub.h*), in mass %, for the linear block copolymers in the diluent oil; and an amount of ester base stock.

The present invention relates to star polymer having a core made up of a crosslinked network of polymers derived from a mixture of one or more multi-functional monomers and one or more mono-functional monomers and where the star polymer has arms made of polymers derived from a mixture of one or more mono-functional monomers, where the star contains at least three arms bonded to the core. The invention further relates to lubricating compositions containing an oil of lubricating viscosity and the described star polymers as well as methods of lubricating a mechanical device with the described lubricating compositions.

A viscosity index improver containing, in diluent oil, one or more optionally functionalized linear block copolymers having at least one block derived from alkenyl arene covalently linked to at least one block derived from diene in an amount that is greater than the critical overlap concentration (c.sub.h*), in mass %, for the linear block copolymers in the diluent oil; and ester base stock and/or at least one star (or radial) polymer, the star polymer being present in an amount such that the c/c.sub.h* value of the star polymer in the concentrate falls within the range of from 0.01 to about 1.6, wherein c is the concentration in mass % of star polymer in the concentrate and c.sub.h* is the critical overlap concentration in mass % for the star polymer in the diluent oil used to form the concentrate.

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.