Use of detergent additives in high-ethanol fuels for deposit control

Abstract

The present invention relates to a method for controlling deposit formation on intake valves while simultaneously exhibiting “no-harm” on combustion chamber deposits in engines by combusting in the engine a fuel composition containing an ethanol content greater than about 5% by volume and a Mannich-base detergent additive. The invention also relates to a high ethanol-content gasoline fuel containing a Mannich-base detergent in an amount effective for improving the reduction of intake valve deposits resulting from the combustion in an engine of the fuel.

1 . A method for reducing the formation of intake valve deposits in an engine having intake valves, the method comprising combusting in an engine a gasoline fuel comprising: 
 a) a gasoline;    b) ethanol present in the fuel in an amount of at least about five volume percent, and    c) a gasoline performance additive comprising a Mannich-based detergent.    
     
     
         2 . The method of  claim 1 , wherein the gasoline is selected from the group consisting of fuel containing hydrocarbons boiling in the gasoline boiling point range of from 90° C. to 400° C.  
     
     
         3 . The method of  claim 1 , wherein the ethanol is present in an amount of at least 24 volume percent.  
     
     
         4 . The method of  claim 1 , wherein the ethanol is present in an amount of at least about 50 volume percent.  
     
     
         5 . The method of  claim 1 , wherein the detergent is a Mannich-base polyisobutylene cresol detergent.  
     
     
         6 . The method of  claim 1 , wherein the fuel has a conductivity greater than 1.0 nS/m.  
     
     
         7 . The method of  claim 6 , wherein the fuel has a conductivity greater than about 100 nS/m.  
     
     
         8 . The method of  claim 1 , wherein formation of combustion chamber deposits in the engine is not increased relative to the amount of combustion chamber deposits formed from the combustion in the engine of the same fuel and ethanol without the addition of the detergent additive.  
     
     
         9 . The method of  claim 8 , wherein the engine is a direct-injection gasoline, spark-ignited engine.  
     
     
         10 . The method of  claim 9 , wherein the engine is supercharged.  
     
     
         11 . The method of  claim 9 , wherein the engine is turbocharged.  
     
     
         12 . A fuel adapted to be combusted in an engine having intake valves, the fuel comprising: 
 a) a gasoline;    b) ethanol present in the fuel in an amount of at least about five volume percent, and    c) a gasoline performance additive comprising a Mannich-based detergent in an amount effective for improving the reduction of intake valve deposits resulting from the combustion in the engine of the fuel.    
     
     
         13 . The composition of  claim 12 , wherein the gasoline is selected from the group consisting of fuel containing hydrocarbons boiling in the gasoline boiling point range of from 90° C. to 400° C.  
     
     
         14 . The composition of  claim 12 , wherein the ethanol is present in an amount of at least 24 volume percent.  
     
     
         15 . The composition of  claim 12 , wherein the ethanol is present in an amount of at least about 50 volume percent.  
     
     
         16 . The composition of  claim 12 , wherein the detergent is a Mannich-base polyisobutylene cresol detergent.  
     
     
         17 . The composition of  claim 12 , wherein fuel has a conductivity greater than 1.0 nS/m.  
     
     
         18 . The composition of  claim 17 , wherein the fuel has a conductivity greater than about 100 nS/m.  
     
     
         19 . The composition of  claim 12 , wherein formation of combustion chamber deposits in the engine is not increased relative to the amount of combustion chamber deposits formed from the combustion in the engine of the same fuel and ethanol without the addition of the detergent additive.  
     
     
         20 . The composition of  claim 12 , wherein the engine is a direct-injection gasoline, spark-ignited engine.  
     
     
         21 . The composition of  claim 20 , wherein the engine is supercharged.  
     
     
         22 . The composition of  claim 20 , wherein the engine is turbocharged.