A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition is formulated to be resistant to turbocharger deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test. The lubricating oil composition may also have a low NOACK volatility, as measured by the method of ASTM D-5800 at 250° C.

A power transmitting fluid comprises a major amount of a lubricating oil and a minor amount of an additive composition. The additive composition comprises: (a) a friction modifier of the formula: ##STR00001## (b) an oil-soluble phosphorus compound; and, (c) an ashless dispersant;
wherein R.sup.1 and R.sup.2 may be the same or different and represent linear or branched, saturated or unsaturated hydrocarbyl groups having from 8 to 20 carbon atoms. Z represents a polyoxyalkylene segment or a polyalkoxylated alkyl amine segment. The friction modifiers provide the fluid with improved fluoroelastomer seal compatibility and enhanced copper corrosion compatibility.

A lubricating composition including: a base oil, a lubricant additive composition including, as a component (A), an organic molybdenum compound of the formula (1) described in the specification, and as a component (B), an amine compound of the formula (2) described in the specification, and a specific metal-based cleaner, wherein a content of the component (B) is 2.9 to 18.6 parts by mass relative to 100 parts by mass of molybdenum atoms of the component (A), and a content of the metal-based cleaner is 0.1% to 10% by mass relative to a total amount of the lubricating composition, wherein the lubricating composition does not include tetraalkyl thiuram disulphide, and wherein the component (A) in terms of the amount of molybdenum atoms is 400 to 1200 ppm by mass relative to a total amount of the lubricating composition.

A lubricating composition including: a base oil, a lubricant additive composition including, as a component (A), an organic molybdenum compound of the formula (1) described in the specification, and as a component (B), an amine compound of the formula (2) described in the specification, and a specific metal-based cleaner, wherein a content of the component (B) is 2.9 to 18.6 parts by mass relative to 100 parts by mass of molybdenum atoms of the component (A), and a content of the metal-based cleaner is 0.1% to 10% by mass relative to a total amount of the lubricating composition, wherein the lubricating composition does not include tetraalkyl thiuram disulphide, and wherein the component (A) in terms of the amount of molybdenum atoms is 400 to 1200 ppm by mass relative to a total amount of the lubricating composition.

A method for reducing timing chain stretch in an engine comprising a step of lubricating said timing chain with a lubricating oil composition that includes a major amount of a base oil; and a minor amount of an additive package including (a) at least one overbased calcium detergent, (b) at least one borated dispersant, (c) a metal dialkyl dithiophosphate, and (d) at least one molybdenum compound. The lubricating oil composition has a TBN value of at least 7.5 mg KOH/g of the lubricating oil composition, at least 80 ppm of molybdenum, based on the total weight of the lubricating oil composition, a weight ratio of total calcium in the lubricating oil composition to total molybdenum in the lubricating oil composition of less than 8.4; and a weight ratio of nitrogen from the dispersant in the lubricating composition to total boron in the lubricating oil composition of from 2.6 to 3.0.

A method for reducing timing chain stretch in an engine comprising a step of lubricating said timing chain with a lubricating oil composition that includes a major amount of a base oil; and a minor amount of an additive package including (a) at least one overbased calcium detergent, (b) at least one borated dispersant, (c) a metal dialkyl dithiophosphate, and (d) at least one molybdenum compound. The lubricating oil composition has a TBN value of at least 7.5 mg KOH/g of the lubricating oil composition, at least 80 ppm of molybdenum, based on the total weight of the lubricating oil composition, a weight ratio of total calcium in the lubricating oil composition to total molybdenum in the lubricating oil composition of less than 8.4; and a weight ratio of nitrogen from the dispersant in the lubricating composition to total boron in the lubricating oil composition of from 2.6 to 3.0.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes greater than 50 wt. % of a base oil of lubricating viscosity, calcium, nitrogen, molybdenum and boron. The weight ratio of Ca:N (ppm/ppm) in the lubricating oil composition is greater than 1.3 to less than 3.0, the weight ratio of Ca:Mo (ppm/ppm) in the lubricating oil composition is greater than 6.7 to less than 56.3, and the weight ratio of Ca:B (ppm/ppm) in the lubricating oil composition is greater than 5.0 to less than 9.8. The lubricating oil composition does not contain added magnesium from a magnesium-containing detergent. The lubricating oil composition is resistant to deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test.

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes greater than 50 wt. % of a base oil of lubricating viscosity, calcium, nitrogen, molybdenum and boron. The weight ratio of Ca:N (ppm/ppm) in the lubricating oil composition is greater than 1.3 to less than 3.0, the weight ratio of Ca:Mo (ppm/ppm) in the lubricating oil composition is greater than 6.7 to less than 56.3, and the weight ratio of Ca:B (ppm/ppm) in the lubricating oil composition is greater than 5.0 to less than 9.8. The lubricating oil composition does not contain added magnesium from a magnesium-containing detergent. The lubricating oil composition is resistant to deposit formation in the boosted internal combustion engine, as shown by its ability to ensure a TCO Temperature Increase of less than 9.0% as measured using the 2015 version of the General Motors dexos1® Turbocharger Coking Test.

A lubricating oil composition including: a lubricant base oil; (A) a calcium salicylate detergent in an amount of 0.005 to 0.03 mass % in terms of calcium on the basis of the total mass of the composition; and (B) a phosphite ester compound represented by the following general formula (1) in an amount of 0.01 to 0.06 mass % in terms of phosphorus on the basis of the total mass of the composition:

##STR00001##

wherein in the general formula (1), R.sup.1 and R.sup.2 are each independently a C5-20 group represented by the following general formula (2):

##STR00002##

wherein in the general formula (2), R.sup.3 is a C2-17 linear chain hydrocarbon group, and R.sup.4 is a C3-17 linear chain hydrocarbon group, and X.sup.1 is an oxygen atom or a sulfur atom.

Provided is a lubricating oil composition having a HTHS viscosity at 150° C. in a range of about 1.7 to about 3.2 mPa s and a low temperature cold cranking viscosity of less than 7,000 mPa s at −20° C., comprising: (a) a major amount of an oil of lubricating viscosity having a kinematic viscosity at 100° C. of from 3.5 mm.sup.2/s to 20 mm.sup.2/s and a viscosity index of greater than 120 with a sulfur content of less than 0.03 wt. %, are classified into the API group III, IV, or V base stock category, and have an aromatics content (C.sub.A) of less than 5%; (b) an organomolybdenum compound; (c) a dispersed hydrated alkali metal borate compound; (e) one or more dispersants; (f) one or more calcium-based metal detergents; and (g) optionally, one or more magnesium-based metal detergents. Also provided is a method for improving wear, high temperature detergency, and thermal stability in an engine comprising operating said engine with said lubricating oil composition.