A lubricating oil composition for a gas engine containing: a base oil (A), at least one overbased calcium detergent (B) selected from the group consisting of calcium salicylate (B1) and calcium phenate (B2), alkenyl succinimide (C), and a hindered amine-based antioxidant (D), where the content (X) of calcium atoms derived from the component (B) is less than 0.090% by mass based on the total amount of the lubricating oil composition; the content (Y) of calcium carbonate contained in the component (B) is 0.060% by mass or more based on the total amount of the lubricating oil composition; the content of boron atoms derived from the component (C) is less than 0.020% by mass based on the total amount of the lubricating oil composition, and the content of the component (D) is more than 0.20% by mass based on the total amount of the lubricating oil composition.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an overbased sodium detergent. The metal overbased detergent may be selected from sulfonate detergents, phenate detergents, and salicylate detergents, including sulfonate detergents with a metal ratio of at least 5.

The lubricant for metal powder metallurgy of the present invention consists of particulates that contain at least one amide compound selected from the group consisting of amide compounds represented by general formula (1) below and amide compounds represented by general formula (2) below, wherein particulates with a particle diameter larger than 198 m are less than 1 mass % and particulates with a diameter of 10 m or less are not more than 10 mass %,
R.sup.1CONHCH.sub.2.sub.mNHCOR.sup.2(1)
wherein, R.sup.1 and R.sup.2 each independently represent a C.sub.13-27 aliphatic hydrocarbon group and m represents a number from 1 to 6,
R.sup.3CONH.sub.2(2)
wherein, R.sup.3 represents a C.sub.13-27 aliphatic hydrocarbon group. The lubricant for metal powder metallurgy of the present invention realizes low rattler values and low densities without inhibition of the lubricity, and can provide green bodies and sintered bodies free of cracking, chipping, and density imbalances.

The invention relates to a method for epilamization of at least one portion of a substrate surface comprising the steps of: a) preparing an epilame agent b) optionally, preparing the substrate surface c) placing the substrate and the epilame agent in a chamber at ambient pressure d) introducing CO.sub.2 into the hermetically sealed chamber at a pressure comprised between 25 bar and 74 bar and at a temperature comprised between 10 C. and 80 C. for a duration comprised between 1 minute and 30 minutes, e) reducing the pressure in the chamber, and f) removing the epilamized substrate from the chamber.

A compound represented by the formula: ##STR00001## wherein each R is independently selected from the group consisting of (i) substituted or unsubstituted alkyl with C=0 to 12 inclusive; wherein X.sup.1, X.sup.2, X.sup.3 and X.sup.4 are each independently selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; wherein R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are each independently selected from the group consisting of alkyl, aryl, alkylaryl groups and hydrogen; and wherein one of R.sup.1 and R.sup.2 and one of R.sup.3 and R.sup.4 may optionally be bridged by a polymethylene group to form a cycloalkyl; wherein when C=0 in R, the combined group R.sup.1 R.sup.2 is the same as the combined group R.sup.3 R.sup.4; and wherein when C=1 in R, each of R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are hydrogen.

A lubricating oil composition for an internal combustion engine, having (A) a lubricating base oil, (B) magnesium salicylate, (C) calcium salicylate, and (D) a viscosity index improver, wherein the lubricating oil composition has an HTHS viscosity at 150? C. of 1.7 mPa.Math.s or more and 2.3 mPa.Math.s or less, and an HTHS viscosity at 100? C. of 4.8 mPa.Math.s or less, can provide a lubricating oil composition for an internal combustion engine provided with high fuel-saving performance.

A lubricating oil composition for an internal combustion engine, having (A) a lubricating base oil including one or more mineral oil-based base oils and having a kinematic viscosity at 100? C. of 2.5 mm.sup.2/s or more and 4.0 mm.sup.2/s or less, and (B) magnesium salicylate in an amount of 0.1 mass % or more and 10 mass % or less based on a total amount of the composition, wherein the composition has an HTHS viscosity at 150? C. of 1.6 mPa.Math.s or more and 2.5 mPa.Math.s or less. The lubricating oil composition for an internal combustion engine has both high fuel-saving performance and LSPI-reducing effect.

The invention is directed to a method for reducing low speed pre-ignition events in a spark-ignited direct injection internal combustion engine by supplying to the sump a lubricant composition which contains an oil of lubricating viscosity and an oil soluble metal compound, wherein the metal of the oil soluble metal compound may be a group (IV) metal, which may be titanium or zirconium.

Provided are: a lubricating oil composition containing a mineral oil (A) having a kinematic viscosity at 40 C. of 5 to 15 mm.sup.2/s and a flash point of 180 C. or higher, a synthetic oil (B) having a kinematic viscosity at 40 C. of 5 to 15 mm.sup.2/s and a flash point of 190 C. or higher, an amide compound (C) and a polyol ester compound (D), which has a low viscosity and fuel saving performance, which can be used in high-temperature environments, and which has excellent gear anti-seizing property and anti-shudder performance; and a lubrication method and a transmission using the lubricating oil composition.

A lubricant composition for a direct injected, boosted, spark ignited internal combustion engine that contains at least one non-sulfur-phosphorus containing zinc compound is disclosed. This disclosure also relates to a method for preventing or reducing low speed pre-ignition in an engine lubricated with a formulated oil. The formulated oil has a composition comprising at least one oil soluble or oil dispersible non-sulfur-phosphorus containing zinc compound.