The disclosure provides (i) a lubricating oil composition including a base oil (A) with a kinematic viscosity at 100 C. of 8.2-12.6 mm.sup.2/s and a saturated hydrocarbon content of 90% by mass or more, a metallic detergent (B) and a zinc dithiophosphate (C), wherein a content of the metallic detergent (B) is 2.5 mmol or more as a soap content concentration per 100 g of the composition, a phosphorous content is 200-1000 mass ppm, and a base number is 7.5 mg KOH/g or more, and (ii) a lubricating oil composition including the base oil (A), the metallic detergent (B), the zinc dithiophosphate (C) and an amine-based antioxidant (E), wherein a content of the amine-based antioxidant (E) is 0.3% by mass or more in terms of total content of the composition, a base number is 6.5 mg KOH/g or more, and a phosphorous content is 200-1000 mass ppm.

Provided is a lubricating oil composition for internal combustion engine, which further reduces the friction to exhibit excellent fuel efficiency performance. A lubricating oil composition for internal combustion engine, which contains (A) a lubricant base oil having a dynamic viscosity of 2.0 to mm.sup.2/s at 100 C., (B) a molybdenum-based friction modifier in an amount of 0.005 to 0.2% by mass, in terms of a molybdenum content, based on the mass of the composition, (C) a salicylate-based metal detergent in an amount of 0.01 to 1% by mass, in terms of a metal content, based on the mass of the composition, and (D) at least one compound selected from amino acids having an alkyl group, alkenyl group, or acyl group having 15 to 24 carbon atoms and/or derivatives thereof in an amount of 0.01 to 10% by mass.

Disclosed is a lubricating oil composition comprising an oil of lubricating viscosity and an oil soluble synergistic mixture of antioxidants, said mixture comprising: a) a hindered amine antioxidant according to formula (I)

##STR00001## wherein each R.sup.1 is independently selected from a substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; R.sup.2 is selected from the group consisting of a hydrogen atom or a, substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; each R.sup.3 is independently selected from the group consisting of a hydrogen atom or a, substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; each R.sup.4 is independently selected from the group consisting of a hydrogen atom or a, substituted or unsubstituted, branched or linear, C.sub.1-C.sub.20 hydrocarbyl group; n is an integer from 1 to 4; and m is an integer from 1 to 5; and b) a molybdenum succinimide complex.

The lubricating oil composition includes an oil of lubricating viscosity, one or more compounds containing a carboxylic acid functional group or ester functional group the compound represented by

##STR00001##

each R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5, and R.sup.6 is independently hydrogen or hydrocarbyl group; at least one of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 is a hydrocarbyl group; and a poly alkylene glycol represented by

##STR00002##

each R.sup.7, R.sup.8, and R.sup.9 is independently hydrogen or hydrocarbyl group and n is from 5 to 1000.

The invention provides a lubricating composition containing a -amino compound. The invention further relates to a method of lubricating an internal combustion engine by lubricating the engine with the lubricating composition. The invention further relates to the use of the -amino carbonyl compound as copper corrosion inhibitors, friction control agents, antiwear and/or extreme pressure agents.

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.

The present invention provides a lubricating oil composition comprising: (a) a major amount of a lubricating oil, (a) a diarylamine antioxidant, and (b) an amidine compound of Formula (I), ##STR00001## wherein R.sub.1 is hydrogen, an alkyl or an aromatic group containing 1-30 carbon atoms; x is from 1 to 5; Y is an optional linking alkyl group; Z is carbon or nitrogen; and R.sub.2 is hydrogen or alkyl groups containing 1-30 carbon atoms. Also provided is a method for lubricating an engine comprising lubricating the engine with said lubricating oil composition.

The present invention relates to lubricant compositions for motorcycle engines where the crankcase lubricant is also used to lubricate a wet clutch. The lubricant compositions contain antimony dithiocarbamates in combination with one or more ash-free friction modifiers.

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 present invention relates to an engine oil lubricant composition for use in internal combustion engines comprising one or more molybdenum containing compounds that deliver 1-1000 ppm molybdenum to the finished oil, one or more phosphorus containing compounds that deliver 25-650 ppm phosphorus to the finished oil, and one or more poly(meth)acrylate viscosity index improvers (VI improvers) that may or may not be functionalized, for improved fuel economy and turbocharger related deposits. In addition, the composition comprises an antioxidant system which is carefully balanced to provide improved fuel economy, comprising an aminic antioxidant, a phenolic antioxidant and an ashless dithiocarbamate. Additionally, the formulated oil may contain a dispersant poly(meth)acrylate, in addition to the PAMA VI improver, to reduce the amount of traditional succinimide dispersants.