Provided are a lubricating oil composition having a high intermetallic friction coefficient and having excellent clutch anti-shudder performance of excellent initial clutch anti-shudder performance and a long clutch anti-shudder lifetime, and a lubrication method and a transmission using the lubricating oil composition. The lubricating oil composition contains an amide compound (A) having a specific structure, a metal-based detergent (B), and at least one phosphorus acid ester (C) selected from an acid phosphate ester and an acid phosphite ester; and the lubrication method and the transmission use the lubricating oil composition.

Disclosed is a lubricating oil composition comprising: a major amount of an oil of lubricating viscosity, and an salicylate compound derived from isomerized normal alpha olefin (NAO) having from about 10 to about 40 carbon atoms, wherein the TBN of the salicylate compound is at least 600 mg KOH/g on an actives basis, and wherein the lubricating oil composition contains from about 0.12 to about 0.17 wt. % of calcium and is substantially free of magnesium. Also provided is a method of lubricating an engine with said lubricating oil composition.

Provided is a lubricating oil composition for engine equipped with a forced-induction mechanism capable of lowering the frequency of occurrence of LSPI, while using a calcium-based detergent. The lubricating oil composition for engine equipped with a forced-induction mechanism contains a base oil (A), a metal-containing surfactant (B) containing at least a calcium-containing surfactant (b1), and at least one basic compound (C) selected from a metal carbonate, a metal hydroxide, and an amine-based compound, wherein the content of sulfur contained in the metal-containing surfactant (B) is 0.2 mass % or more on the basis of the whole amount of the metal-containing surfactant (B); the content of a calcium atom is 0.08 to 0.20 mass % on the basis of the whole amount of the composition; and a mass ratio of the content of the basic compound (C) and the content of a calcium atom derived from the calcium-containing surfactant (b1) [(content of (C))/(calcium content derived from (b1))] is 2.0 or more.

Provided is a lubricating oil composition for engine equipped with a forced-induction mechanism capable of lowering the frequency of occurrence of LSPI, while using a calcium-based detergent. The lubricating oil composition for engine equipped with a forced-induction mechanism contains a base oil (A), a metal-containing surfactant (B) containing at least a calcium-containing surfactant (b1), and at least one basic compound (C) selected from a metal carbonate, a metal hydroxide, and an amine-based compound, wherein the content of sulfur contained in the metal-containing surfactant (B) is 0.2 mass % or more on the basis of the whole amount of the metal-containing surfactant (B); the content of a calcium atom is 0.08 to 0.20 mass % on the basis of the whole amount of the composition; and a mass ratio of the content of the basic compound (C) and the content of a calcium atom derived from the calcium-containing surfactant (b1) [(content of (C))/(calcium content derived from (b1))] is 2.0 or more.

The present invention is directed to a use of a lubricant in a diesel engine to disperse soot produced by the diesel engine, the soot being dispersed without adversely affecting the viscosity of the lubricant; the lubricant comprising a major amount of oil of lubricating viscosity and a minor amount of a dispersant comprising (i) one or more olefin, (ii) one or more carboxylic acid, (iii) one or more polyetheramines and (iv) one or more aromatic amines along with co-additives.

The present invention is directed to a use of a lubricant in a diesel engine to disperse soot produced by the diesel engine, the soot being dispersed without adversely affecting the viscosity of the lubricant; the lubricant comprising a major amount of oil of lubricating viscosity and a minor amount of a dispersant comprising (i) one or more olefin, (ii) one or more carboxylic acid, (iii) one or more polyetheramines and (iv) one or more aromatic amines along with co-additives.

The present invention relates to a metal compound of calixarene not containing sulfur and dispersible in oil, which can be partially salified, or neutral, or basic or overbased, said calixarene having general formula (I) in which: a) R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from hydrogen, or a group containing carbon and hydrogen, or a group containing in addition to carbon and hydrogen also heteroatoms, provided that said heteroatoms are not sulfur; b) one of the two substituents R.sub.5 and R.sub.6 is hydrogen, while the other may be selected from hydrogen, or a linear or branched alkyl with a number of carbon atoms between 1 and 6, preferably methyl, ethyl, 1-propyl, 2-propyl, n-butyl, sec-butyl, more preferably methyl or ethyl; c) n is the number of units of the calixarene ring and is comprised in the range between 4 and 16, preferably between 5 and 12; said calixarene being characterized in that in at least one of the n units of the calixarene ring, at least one of the substituents R.sub.1, R.sub.2, R.sub.3 and R.sub.4 contains at least one acid group of carboxylic type available for the reaction with a metal base, with the proviso that said acid group of carboxylic type is not contained in a unit of the calixarene ring derived from salicylic acid. ##STR00001##

The present invention relates to a metal compound of calixarene not containing sulfur and dispersible in oil, which can be partially salified, or neutral, or basic or overbased, said calixarene having general formula (I) in which: a) R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are independently selected from hydrogen, or a group containing carbon and hydrogen, or a group containing in addition to carbon and hydrogen also heteroatoms, provided that said heteroatoms are not sulfur; b) one of the two substituents R.sub.5 and R.sub.6 is hydrogen, while the other may be selected from hydrogen, or a linear or branched alkyl with a number of carbon atoms between 1 and 6, preferably methyl, ethyl, 1-propyl, 2-propyl, n-butyl, sec-butyl, more preferably methyl or ethyl; c) n is the number of units of the calixarene ring and is comprised in the range between 4 and 16, preferably between 5 and 12; said calixarene being characterized in that in at least one of the n units of the calixarene ring, at least one of the substituents R.sub.1, R.sub.2, R.sub.3 and R.sub.4 contains at least one acid group of carboxylic type available for the reaction with a metal base, with the proviso that said acid group of carboxylic type is not contained in a unit of the calixarene ring derived from salicylic acid. ##STR00001##

A lubricating composition suited to use in lubricating an internal combustion engine includes an oil of lubricating viscosity and a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or metal salt thereof, wherein the polyolefin is derived from a isobutylene having a number average molecular weight of 150 to 800.

A lubricating composition suited to use in lubricating an internal combustion engine includes an oil of lubricating viscosity and a compound comprising a polyolefin-substituted bridged hydroxyaromatic compound or metal salt thereof, wherein the polyolefin is derived from a isobutylene having a number average molecular weight of 150 to 800.