Fuel compositions for direct injection gasoline engine containing mannich detergents

Abstract

Deposits in a direct injection gasoline engine are reduced by providing as fuel for the operation of said direct injection engine a fuel composition comprising a Mannich detergent.

We claim:  
     
         1 . A method of controlling deposits in a direct injection gasoline engine, said method comprising providing as fuel for the operation of said direct injection engine a fuel composition comprising a Mannich base detergent in proportions effective to reduce the volume of deposits in a direct injection gasoline engine operated on a spark-ignition fuel containing an deposit-controlling amount of said Mannich base detergent to below the volume of deposits in said direct injection gasoline engine operated in the same manner on the same spark-ignition fuel except that it is devoid of Mannich base detergent.  
     
     
         2 . The method of  claim 1  wherein said deposits comprise injector deposits.  
     
     
         3 . The method of  claim 1  wherein the spark-ignition fuel comprises gasoline.  
     
     
         4 . The method of  claim 1  wherein the spark-ignition fuel comprises a blend of hydrocarbons of the gasoline boiling range and at least one fuel-soluble oxygenated compound.  
     
     
         5 . The method of  claim 1  wherein the fuel composition further comprises a carrier fluid selected from the group consisting of 1) a mineral oil or a blend of mineral oils that have a viscosity index of less than about 120, 2) one or more poly-α-olefin oligomers, 3) one or more poly (oxyalkylene) compounds having an average molecular weight in the range of about 500 to about 3000, 4) one or more polyalkenes, 5) one or more polyalkyl-substituted hydroxyaromatic compounds and 6) mixtures thereof.  
     
     
         6 . The method of  claim 5  wherein the carrier fluid comprises at least one poly (oxyalkylene) compound.  
     
     
         7 . The method of  claim 1  wherein the fuel composition further comprises at least one additive selected from the group consisting of antioxidants, carrier fluids, metal deactivators, dyes, markers, corrosion inhibitors, biocides, antistatic additives, drag reducing agents, demulsifiers, dehazers, anti-icing additives, antiknock additives, anti-valve-seat recession additives, lubricity additives and combustion improvers.  
     
     
         8 . A method for operating an direct injection gasoline engine on an unleaded fuel composition which comprises introducing into a direct injection gasoline engine with the combustion intake charge a fuel composition comprising a) a spark-ignition fuel and b) a Mannich detergent.  
     
     
         9 . The method of  claim 8  wherein the spark-ignition fuel comprises gasoline.  
     
     
         10 . The method of  claim 8  wherein the spark-ignition fuel comprises a blend of hydrocarbons of the gasoline boiling range and at least one fuel-soluble oxygenated compound.  
     
     
         11 . The method of  claim 8  wherein the fuel composition further comprises a carrier fluid selected from the group consisting of 1) a mineral oil or a blend of mineral oils that have a viscosity index of less than about 120, 2) one or more poly-α-olefin oligomers, 3) one or more poly (oxyalkylene) compounds having an average molecular weight in the range of about 500 to about 3000, 4) one or more polyalkenes, 5) one or more polyalkyl-substituted hydroxyaromatic compounds and 6) mixtures thereof.  
     
     
         12 . The method of  claim 11  wherein the carrier fluid comprises at least one poly (oxyalkylene) compound.  
     
     
         13 . The method of  claim 8  wherein the fuel composition further comprises at least one additive selected from the group consisting of antioxidants, carrier fluids, metal deactivators, dyes, markers, corrosion inhibitors, biocides, antistatic additives, drag reducing agents, demulsifiers, dehazers, anti-icing additives, antiknock additives, anti-valve-seat recession additives, lubricity additives and combustion improvers.