Lubricating Compositions

Abstract

A method of lubricating an internal combustion engine with a power output of at least 1600 kilowatts, with a lubricating composition, the method comprising: (1) monitoring one or more performance characteristics of the engine; (2) selecting an additive package to provide a desired TBN level to a lubricating composition to modify the performance characteristics of the engine; (3) combining the additive package of step (2) with (a) a component having a viscosity of about 2 mm 2 /s to 12 mm 2 /s, comprising a light neutral base oil, and optionally (b) a component having a viscosity of above 12 mm 2 /s to about 40 mm 2 /s, comprising heavy neutral base oil or a brightstock, to form a lubricating composition; and (4) supplying the lubricating composition of step (3) to the engine.

1 . A method of lubricating an internal combustion engine with a power output of at least 1600 kilowatts, with a lubricating composition, the method comprising:
 (1) monitoring one or more performance characteristics of the engine;   (2) selecting an additive package to provide a desired TBN level to a lubricating composition to modify the performance characteristics of the engine;   (3) combining the additive package of step (2) with (a) a component having a viscosity of about 2 mm 2 /s to 12 mm 2 /s, comprising a light neutral base oil, and optionally (b) a component having a viscosity of above 12 mm 2 /s to about 40 mm 2 /s, comprising heavy neutral base oil or a brightstock, to form a lubricating composition; and   (4) supplying the lubricating composition of step (3) to the engine;   
     wherein the lubricating composition has a total base number of at least 10 mg KOH/g; and wherein the component comprising the light neutral base oil is supplied from an oil reservoir available to said internal combustion engine. 
   
   
       2 . The method of  claim 1 , wherein the total base number of the lubricating composition is about 30 or higher. 
   
   
       3 . The method of  claim 1 , wherein the internal combustion engine has a power output of at least about 3000 kilowatts. 
   
   
       4 . The method of  claim 1 , wherein the internal combustion engine is a 2-stroke marine diesel engine. 
   
   
       5 . The method of  claim 1 , wherein the light neutral base oil is provided from a new or used crankcase system oil. 
   
   
       6 . The method of  claim 1 , wherein the total base number of the lubricating composition is 30 mg KOH/g or higher. 
   
   
       7 . The method of  claim 1 , wherein the one or more characteristics of the engine comprise wear, engine load, variation in TBN, deposits, or corrosion. 
   
   
       8 . The method of  claim 1 , wherein said reservoir is a day tank or cylinder oil service tank or a storage tank. 
   
   
       9 . The method of  claim 1 , wherein the additive package of step (2) is combined with a base oil in a blender. 
   
   
       10 . The method of  claim 1  wherein the additive package of step (2) further comprises at least one performance additive comprising a polymeric thickener, a dispersant, an antiwear agent, a detergent or mixtures thereof. 
   
   
       11 . The method of  claim 10 , wherein the polymeric thickener comprises polyisobutylene with a weight average molecular weight Mw of more than about 8000 to about 25,000 or a poly(meth)acrylate with a weight average molecular weight Mw of about 20,000 to about 300,000. 
   
   
       12 . The method of  claim 10 , wherein the detergent comprises a sulphonate, a phenate or mixtures thereof. 
   
   
       13 . The method of  claim 10 , wherein the dispersant comprises a polyisobutylene succinimide. 
   
   
       14 . The method of  claim 10 , wherein the antiwear agent comprises a metal hydrocarbyl dithiophosphate. 
   
   
       15 . The method of  claim 1 , wherein the light neutral base oil is present at about 50 to about 99.9 weight percent of the lubricating composition; the heavy neutral base oil or brightstock is present at about 0.01 to about 25 weight percent of the lubricating composition; and at least one performance additive is present at about 0.01 to about 25 weight percent of the lubricating composition. 
   
   
       16 . The use of a system oil additised with an additive package to make a cylinder lubricant. 
   
   
       17 . The use of the system oil of  claim 16 , as a cylinder lubricant in a 2-stroke marine diesel engine. 
   
   
       18 . The use of the system oil of  claim 16 , wherein the system oil is from used crankcase system oil.