Sulfur containing lubricating oil additive system particularly useful for natural gas fueled engines

Abstract

A lubricating oil comprising a major amount of at least one of Group II, III, and IV base oil and a minor amount of 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate. A method of making this lubricating oil and a method of lubricating a natural gas engine with this lubricating oil.

What is claimed is:  
     
         1 . Lubricating oil comprising a minor amount of one or more hindered phenols of the general formula:  
       
         
           
           
               
               
           
         
       
       and a major amount of at least one of Group II, III and IV base oils.  
     
     
         2 . Lubricating oil of  claim 1  wherein about 0.2 wt. % to about 3 wt. % of the lubricating oil comprises the hindered phenol of  claim 1 .  
     
     
         3 . Lubricating oil of  claim 1  wherein the hindered phenol is liquid.  
     
     
         4 . A additive formulation comprising the hindered phenol of  claim 1  and one or more dispersants, one or more detergents and one or more wear inhibitors.  
     
     
         5 . Lubricating oil of  claim 1  having a total base number of about 2.15 to about 8.88 as determined by ASTM D 2896.  
     
     
         6 . Lubricating oil of  claim 1  having a total ash content of about 0.1 wt. % to about 1.5 wt. % as determined by ASTM D874.  
     
     
         7 . Lubricating oil of  claim 1  having less than 4000 ppm sulfur.  
     
     
         8 . A method of making the lubricating oil of  claim 1  by combining the hindered phenol of  claim 1  with the base oil of  claim 1  in any order and mixing.  
     
     
         9 . A method of lubricating engines comprising lubricating one or more engines with lubricating oil comprising the hindered phenol of  claim 1 .  
     
     
         10 . Lubricating oil comprising a major amount of at least one of Group II, III and IV base oil and a minor amount of 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate.  
     
     
         11 . Lubricating oil of  claim 10  having less than 4000 ppm sulfur.  
     
     
         12 . Lubricating oil of  claim 10 , wherein about 0.2 wt. % to about 3 wt. % of the lubricating oil comprises 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate.  
     
     
         13 . Lubricating oil of  claim 10 , wherein the 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate is liquid.  
     
     
         14 . Lubricating oil of  claim 10  having a total base number of about 2.15 to about 8.88 as determined by ASTM D 2896.  
     
     
         15 . Lubricating oil of  claim 10  having a total ash content of about 0.1 wt. % to about 1.5 wt. % as determined by ASTM D874.  
     
     
         16 . A method of lubricating engines comprising contacting the engine with the lubricating oil of  claim 10 .  
     
     
         17 . A method for making the lubricating oil of  claim 10  comprising combining the 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate with at least one of Group II, III and IV base oil in any order and mixing.  
     
     
         18 . An additive formulation comprising 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate; one or more dispersants; one or more wear inhibitors; and at least one of sulfonate, salycilate and phenate detergents.  
     
     
         19 . Lubricating oil comprising a minor amount of the additive formulation of  claim 18  and a major amount of at least one of Group II, III and IV base oil.  
     
     
         20 . Lubricating oil of  claim 19  comprising about 4 wt. % to about 16.50 wt. % of the additive formulation and about 40 wt. % to about 97 wt. % of the base oil.  
     
     
         21 . A method for lubricating a natural gas fueled engine comprising lubricating the natural gas fueled engine with the lubricating oil of  claim 19 .  
     
     
         22 . A method for making the additive formulation of  claim 18 , comprising combining one or more detergents; one or more dispersants; one or more wear inhibitors; and 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate in any order and agitating until mixed.  
     
     
         23 . Lubricating oil comprising: 
 about 1 wt. % to about 8 wt. % of one or more dispersants;    about 1 wt. % to about 8.5 wt. % of one or more detergents;    about 0.2 wt. % to about 1.5 wt. % of one or more wear inhibitors;    about 0.2 wt. % to about 3 wt. % 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate; and    about 6 wt. % to about 97 wt. % of at least one of Group II, III and IV base oil.    
     
     
         24 . A method for lubricating a natural gas fueled engine comprising lubricating the natural gas fueled engine with the lubricating oil of  claim 23 .  
     
     
         25 . Lubricating oil comprising: 
 about 1 wt. % to about 8 wt. % of one or more dispersants;    about 1 wt. % to about 8.5 wt. % of one or more detergents;    about 0.2 wt. % to about 1.5 wt. % of one or more wear inhibitors;    about 0.6 wt. % to about 2.5 wt. % 2-(4-hydroxy-3,5-di-t-butyl benzyl thiol) acetate; and    about 6 wt. % to about 97 wt. % of at least one of Group II, III and IV base oil.    
     
     
         26 . A method of lubricating engines comprising contacting one or more engines with the lubricating oil of  claim 25.