The disclosed technology relates to an automotive gear oil, which may be used, for example, in heavy duty manual transmissions and axles, and includes an oil of lubricating viscosity, 1 wt % or less of a dispersant, and at least one boron containing compound.

A lubricating oil composition and method of lubricating an engine equipped with a diesel particulate filter using the lubricating oil composition. The lubricating oil composition may contain greater than 50 wt. % of a base oil of lubricating viscosity, an amount of one or more calcium-containing detergents to provide less than 1700 ppm calcium, an amount of one or more magnesium-containing detergents to provide less than 450 ppm magnesium, an amount of one or more molybdenum-containing compounds to provide less than 450 ppm molybdenum, from about 700 ppm to about 900 ppm of phosphorus, and a total sulfated ash content of no greater than 1.0 wt. %, all as measured by ASTM D874, based on the total weight of the lubricating oil composition; and a ratio, in ppm, of calcium from the one or more calcium-containing detergents to magnesium from the one or more magnesium-containing detergents of 1:1 or more.

The invention is directed to a zinc-free lubricating composition for an internal combustion engine containing a phosphorus anti-wear agent, an ashless antioxidant, and an oxyalkylated phenol compound. The lubricating composition provides wear protection, deposit control, and improved acid control with reduced levels of metal-containing additives.

A method for improving wear control of a steel surface lubricated with a lubricating oil through the generation of thick tribofilms. The method includes: (i) using as the lubricating oil a formulated oil, the formulated oil having a composition comprising at least one lubricating oil base stock as a major component; and at least one lubricating oil additive, as a minor component; and (ii) forming a tribofilm on the steel surface. In time-step tribofilm formation measurements of the lubricating oil by a mini-traction machine (MTM) at constant slide-to-roll ratio (SRR), the saturation traction coefficient (f.sub.s), which correlates to tribofilm thickness on the steel surface, is greater than about 0.11. In the method of this disclosure, elongation of timing chain due to wear of chain link pins is less than about 0.07%, as determined by Ford Chain Wear (FCW) test conducted in accordance with ILSAC GF-6 specification. The lubricating oils are useful in internal combustion engines.

The disclosed technology relates to a lubricant composition for use in an automatic transmission of a hybrid electric vehicle, containing an oil of lubricating viscosity, at least one borate ester, and at least one phosphorus containing compound.

Provided is a lubricating oil composition having a HTHS viscosity at 150 C. in a range of about 1.7 to about 3.2 mPa s and a low temperature cold cranking viscosity of less than 7,000 mPa s at 20 C., comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100 C. of from 3.5 mm.sup.2/s to 20 mm.sup.2/s and a viscosity index of greater than 120 with a sulfur content of less than 0.03 wt. %, are classified into the API group III, IV, or V base stock category, and have an aromatics content (C.sub.A) of less than 5%; (b) an organomolybdenum compound; (c) a dispersed hydrated alkali metal borate compound; (e) one or more dispersants; (f) one or more calcium-based metal detergents; and (g) optionally, one or more magnesium-based metal detergents.

Also provided is a method for improving wear, high temperature detergency, and thermal stability in an engine comprising operating said engine with said lubricating oil composition.

A lubricant composition comprising (a) an oil having a kinematic viscosity at 100 C. of 2.2 to 3.7 mm.sup.2/s; at least one borate ester having an alkyl group of 4 to 18 carbon atoms in an amount to provide 25 to 150 parts per million by weight boron to the composition; and (c) at least one phosphorus ester in an amount to provide 150 to 650 parts per million by weight phosphorus to the composition, wherein the kinematic viscosity at 100 C. of the lubricant composition is less than or equal to 4.7 mm.sup.2/s, provides wear resistance to a needle bearing in an automatic transmission.

A method for preventing or reducing low speed pre-ignition in an engine lubricated with a lubricating oil while maintaining or improving cleanliness by using as the lubricating oil a formulated oil. The formulated oil has a composition including a lubricating oil base stock as a major component, and at least one boron-containing compound and at least one overbased calcium detergent as minor components. The at least one boron-containing compound includes at least one borated dispersant, or a mixture of a boron-containing compound and a non-borated dispersant. The boron to nitrogen ratio for the at least one boron-containing compound is less than or equal to about 0.3 and the lubricating oil is essentially free of elemental magnesium. The lubricating oils of this disclosure are particularly advantageous as passenger vehicle engine oil (PVEO) products.

A lubricating oil composition may contain a base oil (A) and a dispersant-type viscosity index improver (B), in which the nitrogen atom content based on the solid content of the dispersant-type viscosity index improver (B) is 0.50 to 1.50% by mass, and the weight-average molecular weight (Mw) thereof is 100,000 or more, and the content in terms of the solid content based on the total amount of the composition of the dispersant-type viscosity index improver (B) is more than 0.05% by mass and less than 5.0% by mass. The lubricating oil composition may exert excellent wear resistance in a state contaminated with soot.

A process for producing a borated polyalkenyl succinimide dispersant composition in which the boron is incorporated primarily as cyclic metaboric acid moieties and the equivalents of boron incorporated per equivalent of nitrogen in the succinimide carrier is greater than 2; in which process a slurry of orthoboric acid is added to a polyalkenyl succinimide to form a reaction mixture, which reaction mixture is then heated under conditions (at a temperature and pressure and for a time) sufficient to remove from the reaction mixture from about 0.8 to about 1.2 moles of water of reaction per mole of boric acid charged.