Method for reducing low speed pre-ignition

Abstract

Use of an unleaded gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the unleaded gasoline fuel composition comprises a gasoline base fuel and detergent additive package, wherein the detergent additive package comprises a Mannich base detergent mixture, wherein the mixture comprises a first Mannich base detergent component derived from a di- or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the spark-ignition internal combustion engine is lubricated with a lubricant composition comprising from 1200 ppmw to 3000 ppmw of calcium, based on the total lubricant composition.

1 . An unleaded gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the unleaded gasoline fuel composition comprises:
 a gasoline base fuel, and   a detergent additive package,   wherein the detergent additive package comprises a Mannich base detergent mixture,   wherein the Mannich base detergent mixture comprises a first Mannich base detergent component derived from a di- or polyamine and a second Mannich base detergent component derived from a monoamine,   wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and   wherein the spark-ignition internal combustion engine is lubricated with a lubricant composition comprising from 1200 ppmw to 3000 ppmw of calcium, based on the total lubricant composition.   
     
     
         2 . The unleaded gasoline fuel composition according to  claim 1  wherein the detergent package further comprises a carrier fluid, preferably selected from the group consisting of a polyether monool and polyether polyol, wherein the weight ratio of carrier fluid to Mannich base detergent mixture ranges from about 0.25:1 to about 1:1. 
     
     
         3 . The unleaded gasoline fuel composition according to  claim 2  wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent ranges from about 1:1 to about 1:3. 
     
     
         4 . The unleaded gasoline fuel composition according to  claim 1  wherein the detergent package further comprises an antiwear component selected from a hydrocarbyl amide and a hydrocarbyl imide. 
     
     
         5 . The unleaded gasoline fuel composition according to  claim 1  wherein the detergent additive package further comprises a succinimide detergent, wherein the weight ratio of succinimide detergent to Mannich base detergent mixture ranges from about 0.04:1 to about 0.2:1. 
     
     
         6 . The unleaded gasoline fuel composition according to  claim 1  wherein the unleaded gasoline fuel composition comprises from about 23 ppm to 2000 ppm by weight of the detergent additive package. 
     
     
         7 . The unleaded gasoline fuel composition according to  claim 1  wherein the detergent additive package is present in the form of an additive concentrate which comprises the detergent additive package and an antiwear component selected from a hydrocarbyl amide and a hydrocarbyl imide. 
     
     
         8 . The unleaded gasoline fuel composition according to  claim 7  wherein the unleaded gasoline fuel composition comprises from about 23 ppm to about 2000 ppm by weight of the additive concentrate. 
     
     
         9 . The unleaded gasoline fuel composition according to  claim 1  wherein the first Mannich base detergent and the second Mannich base detergent are derived from polyisobutenyl phenol and wherein the polyisobutenyl group has a molecular weight ranging from 500 to 1000 Daltons, as determined by gel permeation chromatography. 
     
     
         10 . An unleaded gasoline fuel composition for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in a spark-ignition internal combustion engine, wherein the unleaded gasoline fuel composition comprises:
 a major amount of gasoline base fuel,   a minor amount of a first Mannich base detergent derived from a di- or polyamine and a second Mannich base detergent derived from a monoamine,   an antiwear component selected from a hydrocarbyl amide and a hydrocarbyl imide,   a polyether carrier fluid, and   a succinimide detergent,   wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and   wherein the spark-ignition internal combustion engine is lubricated with a lubricant composition comprising from 1200 ppmw to 3000 ppmw of calcium, based on the total lubricant composition.   
     
     
         11 . The method for reducing the occurrence of Low Speed Pre-Ignition (LSPI) in an internal combustion engine, the method comprising supplying to the engine a fuel composition comprising an unleaded gasoline fuel composition comprising a detergent additive package wherein the detergent additive package comprises Mannich base detergent mixture, wherein the mixture comprises a first Mannich base detergent component derived from a di- or polyamine and a second Mannich base detergent component derived from a monoamine, wherein the weight ratio of the first Mannich base detergent to the second Mannich base detergent mixture ranges from about 1:6 to about 3:1, and wherein the spark-ignition internal combustion engine is lubricated with a lubricant composition comprising from 1200 ppmw to 3000 ppmw of calcium, based on the total lubricant composition.