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.

The invention provides a lubricating composition containing an oil of lubricating viscosity, an ashless thiocarbamate compound having an optionally-substituted hydrocarbyl group on an S-atom and an optionally-substituted hydrocarbyl group on an N-atom, and a boron-containing compound. The invention further relates to a method of lubricating an internal combustion engine with the lubricating composition.

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.

A composition comprising an oil of lubricating viscosity and a compound represented by formula (I) wherein: R.sup.1 and R.sup.2 are each independently a hydrocarbyl group containing from about 4 to about 18 carbon atoms; p and q are each independently 0 or an integer from 1 to 3, and the sum of p and q is 1, 2, 3, 4, 5, or 6. The composition is effective at swelling seals. ##STR00001##

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.

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.

The present invention relates to a lubricating oil composition containing a base oil (A), a molybdenum dithiocarbamate (B), an ester-based ashless friction modifier (C), and a metal salicylate (D), wherein the content of a molybdenum atom derived from the molybdenum dithiocarbamate (B) is 650 ppm by mass or more on the basis of the whole amount of the lubricating oil composition; a content ratio [C/B.sub.Mo] of the ester-based ashless friction modifier (C) to a molybdenum atom derived from the molybdenum dithiocarbamate (B) is 5.0 to 10 in terms of a mass ratio; the content of a salicylate soap group derived from the metal salicylate (D) is 0.50% by mass or more on the basis of the whole amount of the lubricating oil composition; and a kinematic viscosity at 100° C. is 4.0 mm.sup.2/s or more and less than 9.3 mm.sup.2/s, and a high-temperature high-shear viscosity at 150° C. is 1.7 mPa.Math.s or more and less than 2.9 mPa.Math.s. In accordance with the present invention, a viscosity-reduced lubricating oil composition in which nonetheless a molybdenum dithiocarbamate and an ashless friction modifier are jointly used, not only friction can be reduced early after commencement of lubrication, but also such a state can be maintained, is provided.

The present invention relates to a lubricating oil composition containing a base oil (A), a molybdenum dithiocarbamate (B), an ester-based ashless friction modifier (C), and a metal salicylate (D), wherein the content of a molybdenum atom derived from the molybdenum dithiocarbamate (B) is 650 ppm by mass or more on the basis of the whole amount of the lubricating oil composition; a content ratio [C/B.sub.Mo] of the ester-based ashless friction modifier (C) to a molybdenum atom derived from the molybdenum dithiocarbamate (B) is 5.0 to 10 in terms of a mass ratio; the content of a salicylate soap group derived from the metal salicylate (D) is 0.50% by mass or more on the basis of the whole amount of the lubricating oil composition; and a kinematic viscosity at 100° C. is 4.0 mm.sup.2/s or more and less than 9.3 mm.sup.2/s, and a high-temperature high-shear viscosity at 150° C. is 1.7 mPa.Math.s or more and less than 2.9 mPa.Math.s. In accordance with the present invention, a viscosity-reduced lubricating oil composition in which nonetheless a molybdenum dithiocarbamate and an ashless friction modifier are jointly used, not only friction can be reduced early after commencement of lubrication, but also such a state can be maintained, is provided.

A lubricating oil composition for internal combustion engines containing a base oil (A), a metal-based detergent (B) containing a calcium-based detergent (B1), a zinc dialkyldithiophosphate (C), and a molybdenum-containing compound (D), wherein a calcium atom-equivalent content of the calcium-based detergent (B1) is more than 100 ppm by mass and 600 ppm by mass or less, based on a total amount of the composition, a magnesium atom-equivalent content of a magnesium-based detergent (B2) is less than 200 ppm by mass, based on the total amount of the composition, a sodium atom-equivalent content of a sodium-based detergent (B3) is less than 200 ppm by mass, based on the total amount of the composition, a content ratio of phosphorus derived from the zinc dialkyldithiophosphate (C) to calcium derived from the calcium-based detergent (B1) [P/Ca] is 0.25 or more by mass, and a sulfated ash content is 0.7% by mass or less; and a method for producing the composition.