Abstract: A lubricating oil composition favorably employable for trunk piston diesel engines contains an overbased sulfurized alkylphenol calcium salt, at least two (preferably three) overbased alkylsalicylic acid calcium salts having different base ratios and hydrocarbyl groups of different carbon atom numbers, a borated ashless dispersant, and a zinc dihydrocarbyldithiophosphate.

Abstract: A lubricating oil composition comprising a base oil of lubricating viscosity having a kinematic viscosity of 22 to 300 mm2/s at 40° C. and dissolved or dispersed therein the following additives in the following amounts based on a total amount of the lubricating oil composition: (1) an overbased sulfurized alkylphenol calcium salt detergent in an amount of 0.5 to 1.0 wt. % in terms of calcium content, (2) an overbased calcium alkylbenzenesulfonate detergent in an amount of 1.5 to 2.1 wt. % in terms of calcium content, (3) a nitrogen-containing ashless dispersant in an amount of 0.005 to 0.1 wt. % in terms of nitrogen content, and (4) a zinc dihydrocarbyldithiophosphate in an amount of 0.007 to 0.1 wt.

Abstract: A lubricating oil composition comprising a base oil of lubricating viscosity having a kinematic viscosity of 22 to 300 mm2/s at 40° C. and dissolved or dispersed therein the following additives in the following amounts based on a total amount of the lubricating oil composition: (1) an overbased sulfurized alkylphenol calcium salt detergent in an amount of 0.1 to 1.6 wt. % in terms of calcium content, (2) an overbased calcium alkylbenzenesulfonate detergent in an amount of 0.6 to 2.1 wt. % in terms of calcium content, (3) a nitrogen-containing ashless dispersant in an amount of 0.005 to 0.1 wt. % in terms of nitrogen content, and (4) a zinc dihydrocarbyldithiophosphate in an amount of 0.01 to 0.1 wt.

Abstract: A lubricating oil composition having a TBN in the range of 5 to 55 mg KOH/g and containing a major amount of a base oil of lubricating viscosity and a) 0.19 to 2.10 wt %, based on the total amount of the lubricating oil composition, of an overbased calcium carboxylate having a TBN of 100 mg KOH/g or more, wherein the wt % is expressed in terms of the calcium content; b) 0.002 to 0.06 wt %, based on the total amount of the lubricating oil composition, of a bis-succinimide compound, wherein the wt % is expressed in terms of the nitrogen content; and c) 0.007 to 0.15 wt %, based on the total amount of the lubricating oil composition, of a zinc dialkyldithiophosphate having a secondary alkyl group, wherein the wt % is expressed in terms of the phosphorus content.

Abstract: A lubricating oil composition favorably employable for trunk piston diesel engines contains an overbased sulfurized alkylphenol calcium salt, at least two (preferably three) overbased alkylsalicylic acid calcium salts having different base ratios and hydrocarbyl groups of different carbon atom numbers, a borated ashless dispersant, and a zinc dihydrocarbyldithiophosphate.

Abstract: A lubricating oil composition comprising a base oil of lubricating viscosity having a kinematic viscosity of 22 to 300 mm2/s at 40° C. and dissolved or dispersed therein the following additives in the following amounts based on a total amount of the lubricating oil composition: (1) an overbased sulfurized alkylphenol calcium salt detergent in an amount of 0.1 to 1.6 wt. % in terms of calcium content, (2) an overbased calcium alkylbenzenesulfonate detergent in an amount of 0.6 to 2.1 wt. % in terms of calcium content, (3) a nitrogen-containing ashless dispersant in an amount of 0.005 to 0.1 wt. % in terms of nitrogen content, and (4) a zinc dihydrocarbyldithiophosphate in an amount of 0.01 to 0.1 wt.

Abstract: A lubricating oil composition comprising a base oil of lubricating viscosity having a kinematic viscosity of 22 to 300 mm2/s at 40° C. and dissolved or dispersed therein the following additives in the following amounts based on a total amount of the lubricating oil composition: (1) an overbased sulfurized alkylphenol calcium salt detergent in an amount of 0.5 to 1.0 wt. % in terms of calcium content, (2) an overbased calcium alkylbenzenesulfonate detergent in an amount of 1.5 to 2.1 wt. % in terms of calcium content, (3) a nitrogen-containing ashless dispersant in an amount of 0.005 to 0.1 wt. % in terms of nitrogen content, and (4) a zinc dihydrocarbyldithiophosphate in an amount of 0.007 to 0.1 wt.

Abstract: A lubricating oil composition having a TBN in the range of 5 to 55 mg KOH/g and containing a major amount of a base oil of lubricating viscosity and a) 0.19 to 2.10 wt %, based on the total amount of the lubricating oil composition, of an overbased calcium carboxylate having a TBN of 100 mg KOH/g or more, wherein the wt % is expressed in terms of the calcium content; b) 0.002 to 0.06 wt %, based on the total amount of the lubricating oil composition, of a bis-succinimide compound, wherein the wt % is expressed in terms of the nitrogen content; and c) 0.007 to 0.15 wt %, based on the total amount of the lubricating oil composition, of a zinc dialkyldithiophosphate having a secondary alkyl group, wherein the wt % is expressed in terms of the phosphorus content.

Abstract: A lubricating oil composition containing a base oil of lubricating viscosity, overbased sulfurized alkylphenate detergent or its calcium salt, an overbased alkylsulfonate detergent or its calcium salt, an ashless dispersant, and a zinc dialkyldithiophosphate and/or zinc diaryidithiophosphate is described. The lubricating oil composition provides improved heat stability and anti-wear performance in marine diesel engines operated under severe conditions where the cylinder liner temperature may reach 200 to 260° C.

Abstract: A lubricating oil composition containing a base oil of lubricating viscosity, overbased sulfurized alkylphenate detergent or its calcium salt, an overbased alkylsulfonate detergent or its calcium salt, an ashless dispersant, and a zinc dialkyldithiophosphate and/or zinc diaryidithiophosphate is described. The lubricating oil composition provides improved heat stability and anti-wear performance in marine diesel engines operated under severe conditions where the cylinder liner temperature may reach 200 to 260° C.

Abstract: A lubricating oil composition containing a base oil of lubricating viscosity, overbased sulfurized alkylphenate detergent or its calcium salt, an overbased alkylsulfonate detergent or its calcium salt, an ashless dispersant, and a zinc dialkyldithiophosphate and/or zinc diaryldithiophosphate is described. The lubricating oil composition provides improved heat stability and anti-wear performance in marine diesel engines operated under severe conditions where the cylinder liner temperature reach 200 to 260° C.

Abstract: Disclosed are a lubricant composition comprising a major amount of one or more lubricant fluids and at least one polyvalent metal salt of the formaldehyde condensation products of C.sub.12 -C.sub.22 alkyl hydroxy benzoic acid, and a method of preparation of same. Because of the methylenebis structure of the polyvalent metal salts, engine properties such as detergency/dispersancy, thermal stability, hydrolytic stability, oil solubility and especially compatibility with other additives are improved by the use of the composition.