Two-stroke lubricating oils

Abstract

The smoke index of a two-stroke engine is improved by utilizing as the engine lubricant a two-stroke engine oil that comprises a major amount of a GTL base oil.

1 . A two-stroke gasoline engine oil comprising: 
 a major amount of a GTL base oil; and    an effective amount of at least one additive selected from the group consisting of extreme pressure additives, anti-foaming agents, pour point depressants, rust inhibitors, antioxidants, detergents, dispersants and hydrocarbon solvents.    
   
   
       2 . The oil of  claim 1  wherein the GTL base oil has a kinematic viscosity at 100° C. from about 2 cSt to about 50 cSt and a VI greater than 80.  
   
   
       3 . The oil of  claim 2  wherein the GTL base oil is derived from a F-T wax.  
   
   
       4 . The oil of  claim 3  wherein the GTL base oil contains mixtures of cycloparaffins.  
   
   
       5 . The oil of  claim 3  wherein said oil has a smoke index greater than about 75.  
   
   
       6 . A method for reducing the observable smoke emitted from a two-stroke gasoline engine comprising: 
 providing the engine under conditions of use with a mixture of gasoline and a lubricating composition wherein the lubricating composition comprises a major amount of a GTL lubricating base oil.    
   
   
       7 . The method of  claim 6  wherein the GTL base oil has a kinematic viscosity at 100° C. from about 2 cSt to about 50 cSt and a VI greater than about 80.  
   
   
       8 . The method of  claim 6  wherein the GTL base oil is derived from a F-T wax.  
   
   
       9 . In a two-stroke internal combustion engine comprising lubricant, the improvement wherein the lubricant comprises: 
 a major amount of a GTL base oil; an effective amount of at least one additive selected from the group consisting of extreme pressure additives, anti-foaming agents, pour point depressants, rust inhibitors, antioxidants, detergents, dispersants and hydrocarbon solvents; and wherein the smoke index resulting from lubricant is greater than about 75.    
   
   
       10 . The improvement of  claim 9  wherein the GTL base oil has a kinematic viscosity at 100° C. from about 2 cSt to about 50 cSt and a VI greater than about 80.  
   
   
       11 . The improvement of  claim 10  wherein the GTL base oil is derived from a F-T wax.