Combination of a low ash lubricating oil composition and low sulfur fuel

Abstract

A lubricating oil composition for use in an internal combustion engine operated with a fuel having a sulphur content of less than 50 ppm, that contains a minor amount of at least one metal-containing detergent, which lubricating oil composition, when formulated for use in a diesel engine has a total ash content of less than 1.0 wt. %, and when formulated for use in a gasoline engine has a total ash content of less than 0.7 wt. %.

What is claimed is:  
     
         1 . A lubricating oil composition used in, or for use in, a compression ignited (diesel) internal combustion engine operated with diesel fuel having a sulphur content of less than 50 ppm, said lubricating oil composition comprising a major amount of oil of lubricating viscosity, and a minor amount of at least one metal-containing detergent, wherein said lubricating oil composition has a total ash content of less than 1.0 wt. %, based on the total weight of the lubricating oil composition.  
     
     
         2 . The lubricating oil composition as claimed in  claim 1 , wherein the total amount of ash contributed to said lubricating oil composition by said at least one metal-containing detergent is from 0 to less than 0.9 wt. %, based on the total weight of the lubricating oil composition.  
     
     
         3 . A lubricating oil composition used in, or for use in, a spark ignited (gasoline) internal combustion engine operated with gasoline having a sulphur content of less than 50 ppm, said lubricating oil composition comprising a major amount of oil of lubricating viscosity, and a minor amount of at least one metal-containing detergent, wherein said lubricating oil composition has a total ash content of less than 0.7 wt. %, based on the total weight of the lubricating oil composition.  
     
     
         4 . The lubricating oil composition as claimed in  claim 3 , wherein the total amount of ash contributed to said lubricating oil composition by said at least one metal-containing detergent is from 0 to less than 0.6 wt. %, based on the total weight of the lubricating oil composition.  
     
     
         5 . The lubricating oil composition as claimed in  claim 1  wherein said at least one metal-containing detergent comprises at least one salicylate detergent.  
     
     
         6 . The lubricating oil composition as claimed in  claim 5  wherein said at least one metal-containing detergent consists essentially of at least one salicylate detergent.  
     
     
         7 . The lubricating oil composition as claimed in  claim 3  wherein said at least one metal-containing detergent comprises at least one salicylate detergent.  
     
     
         8 . The lubricating oil composition as claimed in  claim 7  wherein said at least one metal-containing detergent consists essentially of at least one salicylate detergent.  
     
     
         9 . A compression ignited (diesel) internal combustion engine operated with diesel fuel having a sulphur content of less than 50 ppm, and lubricated with a lubricating oil composition as claimed in  claim 1 .  
     
     
         10 . The internal combustion engine as claimed in  claim 9 , wherein said engine is a heavy duty diesel engine.  
     
     
         11 . A spark ignited (gasoline) internal combustion engine operated with gasoline having a sulphur content of less than 50 ppm, and lubricated with a lubricating oil composition as claimed in  claim 3 .  
     
     
         12 . The internal combustion engine as claimed in  claim 9 , wherein said engine is equipped with a particulate trap.  
     
     
         13 . The internal combustion engine as claimed in  claim 11 , wherein said engine is equipped with a particulate trap.  
     
     
         14 . The internal combustion engine as claimed in  claim 9 , wherein said engine is equipped with an exhaust gas recirculation system.  
     
     
         15 . The internal combustion engine as claimed in  claim 11 , wherein said engine is equipped with an exhaust gas recirculation system.  
     
     
         16 . The internal combustion engine as claimed in  claim 14 , wherein exhaust gases and/or combustion air is cooled prior to introduction into the engine combustion chamber.  
     
     
         17 . The internal combustion engine as claimed in  claim 15 , wherein exhaust gases and/or combustion air is cooled prior to introduction into the engine combustion chamber.  
     
     
         18 . A method of operating a compression ignited (diesel) internal combustion engine, which method comprises operating said engine with a fuel having a sulphur content of less than 50 ppm, and lubricating said engine with a lubricating oil composition as claimed in  claim 1 .  
     
     
         19 . A method of operating a spark ignited (gasoline) internal combustion engine, which method comprises operating said engine with a fuel having a sulphur content of less than 50 ppm, and lubricating said engine with a lubricating oil composition as claimed in  claim 3.