An environmentally-improved motor oil blend and related methods for properly lubricating components of an engine and favorably modifying a plastic response of components of the engine, the blend being free of zinc di-alkyl-di-thiophosphates (ZDDP) and free of zinc di-thiophosphate (ZDTP), comprising: a motor oil selected from the motor oil group consisting of Group I, Group II, Group III, Group IV, and Group V motor oils; a motor oil additive comprising alpha-olefins and hydroisomerized hydro-treated severe hydrocracked base oil; ZDDP omitted from the chemical constituents of the motor oil; and ZDTP omitted from the chemical constituents of the motor oil.

Lubricating oil compositions may include a base oil, a succinimide compound, and a thioheterocyclic compound. Such compositions may have a sulfur content of 0.10 mass % to 1.00 mass % based on a total amount of the composition. A phosphorus content represented by P in mass % and a sulfated ash content represented by M in mass %, based on the total amount of such compositions, may satisfy any of conditions A to C: condition A: P<0.03, and M<0.3; condition B: P<0.03 and 0.3≦M≦0.6; and condition C: 0.03≦P≦0.06 and M<0.3.

A lubricating oil composition is provided which comprises (a) greater than 50 wt. % of a base oil of lubricating viscosity; and (b) 0.1 to 40 wt. % of an overbased alkaline earth metal alkyl-substituted hydroxyaromatic carboxylate, wherein the alkyl substituent is a residue derived from an isomerized alpha-olefin having from 12 to 40 carbon atoms, and having a TBN, on an actives basis, of less than 600 mg KOH/g, as determined by ASTM D 2896; wherein the lubricating oil composition is a monograde lubricating oil composition meeting specifications for SAE J300 revised January 2015 requirements for a SAE 20, 30, 40, 50, or 60 monograde engine oil, and has a TBN of 5 to 200 mg KOH/g, as determined by ASTM D2896.

[Technical Problem] An object is to provide a sliding system which can drastically reduce the friction coefficient on a sliding portion by means of a novel combination of a chromium nitride film and a lubricant oil. [Solution to Problem] The sliding system according to the present invention includes: a pair of sliding members having sliding surfaces that can relatively move while facing each other; and a lubricant oil that can be interposed between the sliding surfaces facing each other. At least one of the sliding surfaces is formed as a coating surface of a chromium nitride film, and the lubricant oil contains an oil-soluble molybdenum compound that has a chemical structure of a trinuclear of Mo. When the chromium nitride film as a whole is 100 at % (referred simply to as “%”), the chromium nitride film contains 40-65% of Cr and 35-55% of N, and the chromium nitride film has a relative surface area of 15-60% wherein the relative surface area is a surface area ratio of (111) plane to (200) plane obtained when analyzed using X-ray diffraction. The lubricant oil preferably contains 5-800 ppm of the oil-soluble molybdenum compound in a content mass of Mo to the lubricant oil as a whole.

A lubricating composition includes an oil of lubricating viscosity and an oil-soluble dispersant viscosity modifier, which includes an olefin-based polymer backbone and at least one pendent functional group. Each of the at least one pendent functional group is independently attached to the olefin-based polymer backbone by a linking group. The at least one pendent functional group includes a sulfonate moiety.

A method for improving corrosion protection and friction coefficient in an engine or other mechanical component lubricated with a lubricating oil by using as the lubricating oil a formulated oil. The formulated oil has a composition comprising a lubricating oil base stock as a major component, and a mixture of (i) at least one organic molybdenum compound, and (ii) at least one borated ester, as a minor component. Corrosion protection and friction coefficient are improved as compared to corrosion protection and friction coefficient achieved using a lubricating oil containing a minor component other than the mixture of (i) at least one organic molybdenum compound, and (ii) at least one borated ester.

The invention provides a lubricating composition containing an aromatic compound and an oil of lubricating viscosity. The invention further relates to the use of the lubricating composition in an internal combustion engine. The invention further relates to the use of the aromatic compound as an antiwear agent.

The present disclosure describes transmission fluid compositions, additive packages, and methods for lubricating a transmission, particularly transmission fluid compositions having color stability that are able to meet or exceed vehicle transmission fluid specifications for different makes of vehicles. The transmission fluid composition contains a base oil and an additive composition having at least one thiadiazole compound the selected from compounds of the Formulas (I)-(II):

##STR00001##

wherein n is 1-5; R.sup.1 is a substituted or unsubstituted hydrocarbyl group having 1-100 carbon atoms; and R.sup.2 is a hydrogen or is a substituted or unsubstituted hydrocarbyl group having 1-100 carbon atoms, wherein the transmission fluid composition is adapted for use in a transmission.

The invention provides a method of lubricating a compression-ignition internal combustion engine with a maximum laden mass over 2,700 kg comprising supplying to the engine a lubricating composition comprising: an oil of lubricating viscosity, a 300 TBN or higher alkaline earth metal sulphonate detergent having a metal ratio of 10 to 40, 0.1 wt % to 4 wt % of a borated polyisobutylene succinimide dispersant, wherein the polyisobutylene from which the borated polyisobutylene succinimide is derived has a number average molecular weight of 550 to 1150, and 0.1 wt % to 6 wt % of a polyisobutylene succinimide, wherein the polyisobutylene from which polyisobutylene succinimide is derived has a number average molecular weight of 1550 to 2500, 0 wt % to 0.2 wt % of a phenolic based detergent, wherein the total amount of soap delivered by the alkaline earth metal sulphonates (typically calcium sulphonate) is 0.4 to 1 wt % of the lubricating composition, and wherein the lubricating composition has a sulphated ash content of not more than 1.5 wt %.

An environmentally-improved motor oil blend and related methods for properly lubricating components of an engine and favorably modifying a plastic response of components of the engine, the blend being free of zinc di-alkyl-di-thiophosphates (ZDDP) and free of zinc di-thiophosphate (ZDTP), comprising: a motor oil selected from the motor oil group consisting of Group I, Group II, Group III, Group IV, and Group V motor oils; a motor oil additive comprising alpha-olefins and hydroisomerized hydro-treated severe hydrocracked base oil; ZDDP omitted from the chemical constituents of the motor oil; and ZDTP omitted from the chemical constituents of the motor oil.