Lubricating oil compositions are disclosed. The lubricating oil compositions include one or more base oils (A) containing one or more polyalphaolefin (PAO) base oils derived at least in part from a C.sub.12 olefin. The lubricating oil compositions further include from about 65 wt. % to about 85 wt. %, based on the total weight of the lubricating oil composition, of one or more base oils (B) having a kinematic viscosity at 100° C. of from about 3.0 cSt to about 5.5 cSt; and from about 0.1 wt. % to about 10 wt. %, based on the total weight of the lubricating oil composition, of a succinimide dispersant.

The present invention provides a hydraulic fluid comprising: (a) 40 to 150 ppm by weight in terms of nitrogen content of a corrosion inhibiting agent which is one or more compounds of formula (I):

##STR00001## and/or tribologically acceptable salts thereof, wherein in formula (I): each R.sup.1 is independently a hydrocarbyl group comprising 1 to 10 carbon atoms, x is 0 to 4, and R.sup.2 is hydrogen or a hydrocarbyl group containing 1 to 10 carbon atoms; (b) 1500 to 4000 ppm by weight of an ashless nitrogen-containing dispersant; and (c) a major amount of a base oil.

Use of a liquid fuel composition in an internal combustion engine, the internal combustion engine containing a lubricating composition for lubricating said internal combustion engine, wherein the liquid fuel composition comprises at least one nitrogen-containing detergent additive, for the purpose of reducing engine wear caused by the presence of soot in the lubricating composition.

A lubricating oil composition and method for controlling timing chain stretch, wherein the composition contains greater than 50 wt. % of base oil, zinc dialkyl dithiophosphate(s) to provide 350-2200 ppm zinc, molybdenum-containing compound(s) to provide >1-3000 ppm molybdenum, and magnesium-containing detergent(s) to provide <2050 ppm magnesium, all based on the total weight of the composition. The composition has a total TBN of less than 7.5 mg KOH/g, measured by ASTM D-2896 and a weight ratio of ppm of zinc from zinc dialkyl dithiophosphate(s) to ppm of molybdenum from molybdenum-containing compound(s) of <10. The method employs the lubricating oil composition to control timing chain stretch to a level of 0.1% or less.

Lubricating composition comprising (i) base oil and (ii) a Verkade base compound having the formula (1): wherein R.sup.1, R.sup.2 and R.sup.3 are each independently selected from hydrogen and saturated or unsaturated, straight chain or branched, C.sub.1-C.sub.22 alkyl groups. The lubricating composition of the present invention exhibits improved base number retention and oxidative stability, particularly in the presence of a biofuel such as fatty acid alkyl ester.

##STR00001##

A comb copolymer viscosity modifier may be made by polymerization comprising at least, or consisting essentially of, the following monomers: (a) (optionally from 7.0 wt % to 18 wt %, by repeat units, of) a hydrogenated polybutadiene-based (alk)acrylate ester macromonomer; (b) (optionally from 33 wt % to 64 wt %, by repeat units, of) a C.sub.3-C.sub.8alkyl (alk)acrylate ester monomer; (c) a C.sub.12-C.sub.24 alkyl (alk)acrylate ester monomer; and (d) (optionally from 3.0 wt % to 25 wt %, by repeat units, of) H-endcapped, C.sub.1-C.sub.18 alkyl-endcapped, or C.sub.6-C.sub.20 aryl-, aralkyl-, or alkaryl-endcapped C.sub.2-C.sub.6 oxyalkyl or C.sub.2-C.sub.6 oligo(alkylene glycol)-based (alk)acrylate ester monomer, wherein repeat units based on monomer (c) and/or monomer (d) comprise at least 21.0 wt % (and optionally up to 35.0 wt %) of repeat units of the comb copolymer viscosity modifier. Lubricant compositions comprising the comb copolymer viscosity modifier, as well as uses thereof and methods for modifying viscosity and dispersancy, are also contemplated.

A lubricating oil composition comprising greater than 50 wt.% of a base oil of lubricating viscosity, and either: a) an additive composition comprising: one or more zinc, dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of zinc (Zn) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TEN) of the one or more dispersants to the TEN of the lubricating oil composition is a multiplication factor Zn*TBNDisp of at least about 0.06; or b) an additive composition comprising: one or more zinc dialkyl dithiophosphates (ZDDP compounds) and one or more dispersants, wherein the amount of phosphorus (P) in weight percent provided to the lubricating oil composition by the one or more ZDDP compounds multiplied by the contribution of the total base number (TBN) of the one or more dispersants to the TBN of the lubricating oil composition is a multiplication factor P*TBNDisp of at least about 0.051.

Disclosed herein is an overbased alkaline earth metal hydrocarbyl-substituted salicylate detergent comprising both carbonate and borate moieties and exhibiting the following characteristics: a basicity index of at least 3.8; a ratio of soap content to mass % boron is greater than 55 mmol/kg; a soap content of at least 330 mmol/kg; a TBN, measured according to ASTM D2896, of at least 220 mg KOH/g; and a mass ratio of borate to carbonate from 0.75 to 6.0, wherein the alkaline earth metal comprises calcium and/or magnesium, and the hydrocarbyl substitution comprises 9 to 30 carbon atoms. Methods of making the boron-containing salicylate detergent, specifically to be package-stable, are also disclosed, as well as package-stable lubricant additive package concentrates and lubricating oil compositions containing same.

Lubricant compositions including an additive composition and methods for its use in engines that produce soot. The lubricant composition contains a base oil and an additive composition having (a) at least 0.05 percent by weight of a first dispersant that is a reaction product of A) a hydrocarbyl-dicarboxylic acid or anhydride, and B) at least one polyamine; and (b) at least 0.05 percent by weight, both based on a total weight of the lubricant composition, of a second dispersant that is a reaction product of A′) a hydrocarbyl-dicarboxylic acid or anhydride, 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.

Provided are compositions and their use as dispersant and/or detergent additives for lubricants. The compositions comprise an amine alkoxylate of the formula I: (I) wherein R.sup.1-R.sup.7, R.sup.1′-R.sup.7; x, x′, A, A′ and A″ are as defined herein. ##STR00001##