Lubricating oil compositions and methods of their use are provided herein. A lubricating oil composition as described herein includes a major amount of an oil of lubricating viscosity, an amine-functionalized olefin copolymer dispersant viscosity index improver in an amount of from about 1.5 wt. % to 2.0 wt. % based on the weight of the lubricating oil composition, and a dispersant. The amine-functionalized olefin copolymer dispersant viscosity index improver includes a reaction product of an acylated olefin copolymer and a polyamine. The dispersant includes reaction product of components (A) a hydrocarbyl-dicarboxylic acid or anhydride having a number average molecular weight of from about 500 to about 5000 and (B) at least one polyamine, wherein the reaction product is post-treated with (C) an aromatic carboxylic acid, an aromatic polycarboxylic acid, or an aromatic anhydride, wherein all carboxylic acid or anhydride groups are attached directly to an aromatic ring, and/or (D) a non-aromatic dicarboxylic acid or anhydride having a number average molecular weight of less than about 500.

A seal swell agent for a lubricating fluid is described. The invention relates to a seal swell agent for use in lubricating oils, such as engine oils, turbine oils, automatic and manual transmission, or gear, fluids, drivetrain and gear oils and hydraulic fluids. The seal swell agent comprises a diester of sorbitol or a derivative thereof and at least one carboxylic acid. The invention extends to the use of a diester of sorbitol or a derivative thereof and at least one carboxylic acid as a seal swell agent, and a method of maintaining seal integrity.

A power transmitting fluid comprises a major amount of a lubricating oil and a minor amount of an additive composition. The additive composition comprises:

(a) a friction modifier of the formula:

##STR00001##

(b) an oil-soluble phosphorus compound; and,
(c) an ashless dispersant;
wherein R.sup.1 and R.sup.2 may be the same or different and represent linear or branched, saturated or unsaturated hydrocarbyl groups having from 8 to 20 carbon atoms. Z represents a polyoxyalkylene segment or a polyalkoxylated alkyl amine segment. The friction modifiers provide the fluid with improved fluoroelastomer seal compatibility and enhanced copper corrosion compatibility.

A lubricating composition for use in heavy duty diesel engines which is formulated to allow the use of organomolybdenum compounds but which overcomes the issue of Cu and/or Pb corrosion. The lubricant is characterized by having a synergistic additive composition comprising (A) a sulfur-free organo-molybdenum compound, (B) a sulfur-containing organo-molybdenum compound and (C) a triazole derivative prepared by reacting 1,2,4-triazole, a formaldehyde source and an amine; (A), (B) and (C) being present in an amount sufficient to allow the lubricating composition to pass the High Temperature Corrosion Bench Test ASTM D 6594 with respect to Cu and/or Pb corrosion.

A method for improving fuel efficiency and reducing frictional properties while maintaining or improving deposit control, in an engine lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition including from 75 to 95 wt % of lubricating oil base stock including a Group I base stock or a combination of a Group III, Group IV and Group V base stock including from 30 to 35 wt % Group III, 45 to 55 wt % Group IV and 0 to 5 wt % Group V and a friction modifier mixture comprising a polymeric ethoxylated fatty acid ester at from 0.1 to 1.0 wt. % and a mixed glyceride ester at from 0.1 to 1.0 wt. % of the formulated oil. The lubricating engine oils are useful in internal combustion engines including direct injection, gasoline and diesel engines.

A lubricating oil composition containing a lubricating base oil and on the basis of the total mass of the composition, (A) a boron-containing ashless dispersant in an amount of 100 to 500 ppm by mass as boron, (B) a phosphorous additive in an amount of 300 to 800 ppm by mass as phosphorus, (C) an amide- and/or imide-based friction modifier in an amount of 1 to 4 percent by mass, and (D) an alkali metal- and/or alkaline earth metal-based detergent in an amount of 100 to 300 ppm by mass as metal, and having a 40 C. kinematic viscosity of 30 mm2/s or lower is provided. The lubricating oil composition, which has a low viscosity to improve fuel efficiency, also has superior anti-wear, anti-seizure, and anti-shattering properties, even when the composition is degraded by oxidation or by the elution of compounds from sealing materials after long term use.

The present disclosure is directed to an additive composition for engine oils comprising; (a) an alkenyl-substituted succinic anhydride and (b) a polyamine compound and (C) Co-additives, wherein the reaction product has a ratio of the amide to imide infrared absorption peak areas of about 1:1.2 to about 1.6. The said reaction product is effective to prevent engine deposits along with protecting elastomeric seal material of an internal combustion engine and also improves piston cleanliness and ring sticking performance of an internal combustion engine.

The disclosed technology relates to ashless compounds exhibiting neutral pH and having sufficient polarity to act as a dispersant. The disclosed technology additionally relates to the use of the ashless compounds in engine lubricants as dispersants for preventing engine deposit without degrading seals or increasing (i.e. contributing to) corrosion.

The presently claimed invention relates to a lubricant composition comprising at least one beta-glucan, optionally in form of one of its derivatives, at least one base oil, at least one additive component, and optionally water; the use of said lubricant compositions for reducing wear in metal-on-metal contact and the use of at least one beta-glucan for reducing the friction coefficient of a lubricant composition.

The disclosed technology relates to a dispersant composition comprising the reaction product of a polyolefin acylating agent and an amine terminated or hydroxyl terminated polyether. In addition, the technology relates to lubricating compositions containing the dispersant composition and an optional synergistic amount of another dispersant, as well as methods of employing the dispersant composition in an engine and engine oils.