A lubricating oil composition including: a lubricant base oil having a kinematic viscosity at 40° C. of 6.0 to 12.0 mm.sup.2/s; (A) a succinimide dispersant having a polyisobutenyl group having a number average molecular weight of no less than 800, in an amount of no less than 80 mass ppm in terms of nitrogen and no more than 2.7 mass % as the entire compound; (B) a condensation reaction product of an alkyl- or alkenyl-succinic acid having a C8-30 alkyl or alkenyl group or anhydride thereof and a polyamine, or a modified product thereof, or any combination thereof, in an amount of 50 to 1300 mass ppm in terms of nitrogen, wherein the product of the weight average molecular weight of the component (A) and the amount of the component (A) as the entire compound (mass %) is no more than 16,000.

A lubricating oil composition for a transmission, the composition including: (A) a lubricant base oil comprising a mineral base oil and/or a synthetic base oil; and (B) a poly(meth)acrylate having a weight average molecular weight of no more than 25,000, wherein the composition has a kinematic viscosity at 100° C. of 2.5 to 4.9 mm.sup.2/s.

Provided are: a lubricating oil composition for transmissions having a long fatigue life and a low viscosity, which contains a base oil and an olefin copolymer and in which the mass-average molecular weight of the olefin copolymer is 5,000 or more and 30,000 or less, the hydrodynamic radius of the olefin copolymer is 1.00 nm or more and 5.00 nm or less, and the content of the olefin copolymer based on the total amount of the composition is 1.0% by mass or more and 8.0% by mass or less; and a production method for the composition, a lubricating method using a lubricating oil composition for transmissions, and a transmission.

An additive for a lubricating composition includes an ionic tetrahedral borate compound which includes a cation and a tetrahedral borate anion having a boron atom, the boron atom has at least one aliphatic bidentate di-oxo ligand. The cation may be selected to provide detergent and/or dispersant and/or antioxidant properties to a lubricating composition.

A booster additive concentrate may advantageously contain: (a) an anti-wear mixture of two or more phosphite/phosphate compounds and one or more ether/thioether compounds; (b) an ashless dispersant; (c) a calcium-containing detergent, such as an overbased calcium phenate; (d) ≥2 friction modifiers, at least one of which comprises a polyalkylene polyamine succinimide derivative; (e) optionally a corrosion inhibitor; and (f) a lubricating oil basestock. Based on these additive components, the booster additive concentrate may exhibit specific contents of B/Ca/P and may contain minimal or substantially no additional antioxidants. Lubricant compositions can be made from the booster additive concentrates and a fresh/used lubricant oil composition “diluent,” which can rejuvenate the diluent. Such lubricant compositions can have advantageous anti-shudder durability (ASD) lifetimes and other frictional properties. In particular, such concentrates/compositions can offer superior lubrication when used in vehicles with continuously variable transmissions (CVTs).

A lubricant composition comprises an anti-wear and or/friction modifying additive which is an ester of a fatty acid and a polyol. At least 50% by weight of the additive is in the form of a mono-ester, and is preferably a mono-glyceride. The lubricant composition may be used in an internal combustion engine.

A VM concentrate comprising: from about 60 to about 95 parts (and at least 50 wt %) of a diluent oil (e.g., having a KV100 of about 2 cSt to about 40 cSt); and from about 5 parts to about 40 parts (and at least 6.0 wt %) of a linear triblock copolymer characterized by the formula: D′-PA-D″; wherein D′ represents a block derived from diene, PA represents a block derived from monoalkenyl arene, D″ represents a block derived from diene, and the linear triblock copolymer is present in an amount effective to modify a lubricating kinematic viscosity at approximately 100° C. (KV100) of the concentrate, and wherein the KV100 of the concentrate is about 3000 cSt or less. The linear triblock copolymer may additionally or alternatively have a thickening efficiency span of at most 0.5.

This disclosure describes an ashless lubricant additive. The additive is a tertiary amine-containing compound having the following structure:

##STR00001##

where each R.sup.1 and R.sup.5 is independently a linear or branched-chain monovalent hydrocarbyl group having two to about twenty carbon atoms, where each R.sup.2, R.sup.3, and R.sup.4 is independently a hydrogen, a linear or branched-chain monovalent hydrocarbyl group having one to about twenty carbon atoms wherein at least one of R.sup.2, R.sup.3, and R.sup.4 is hydrogen, each m is independently from 0 to 2, each p is independently from 0 to 2, for each cylic moiety m+p is from 2 to 4, and each n is independently from 1 to 6.

A booster additive concentrate may advantageously contain: (a) an anti-wear mixture of two or more phosphite/phosphate compounds and one or more ether/thioether compounds; (b) an ashless dispersant; (c) a calcium-containing detergent, such as an overbased calcium phenate; (d) ≥2 friction modifiers, at least one of which comprises a polyalkylene polyamine succinimide derivative; (e) optionally a corrosion inhibitor; and (f) a lubricating oil basestock. Based on these additive components, the booster additive concentrate may exhibit specific contents of B/Ca/P and may contain minimal or substantially no additional antioxidants. Lubricant compositions can be made from the booster additive concentrates and a fresh/used lubricant oil composition “diluent,” which can rejuvenate the diluent. Such lubricant compositions can have advantageous anti-shudder durability (ASD) lifetimes and other frictional properties. In particular, such concentrates/compositions can offer superior lubrication when used in vehicles with continuously variable transmissions (CVTs).

A composition obtained by reacting an O,O′-dialkyldithiophosphoric acid with a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate, and reacting the product thereof with a dialkylphosphite provides good antiwear protection.