Reducing deposit formation in gasoline engines

A method of reducing formation of fuel injection system deposits containing inorganic alkali metal salt which comprises supplying as the fuel to said injection system a fuel composition comprised of a gasoline fuel containing a trace amount of alkali metal salt and a minor amount of at least one gasoline-soluble complexing agent capable of forming in the gasoline a gasoline-soluble complex with said inorganic alkali metal salt and/or the alkali metal cation thereof, said complexing agent being selected from the group consisting of crown ethers, aza-crown ethers, polycrown ethers, lariat-crown ethers, cryptands, spherands and bridged spherands.

In a method for the production of a gasoline fuel composition comprising at least one fuel component containing an alkali metal-containing impurity in an amount such that the alkali metal content of the finished fuel composition is from about 0.01 to about 10 micrograms per milliliter, the step of blending into the gasoline fuel composition a minor complexing amount of at least one gasoline-soluble complexing agent capable of forming in the gasoline a gasoline-soluble complex with inorganic alkali metal salt and/or the alkali metal cation thereof, said complexing agent being selected from the group consisting of crown ethers, aza-crown ethers, polycrown ethers, lariat-crown ethers, cryptands, spherands and bridged spherands.

A fuel composition which comprises gasoline containing at least one gasoline-soluble complexing agent in an amount of up to 200 pounds per thousand barrels, and wherein said complexing agent is selected from the group consisting of crown ethers, aza-crown ethers, polycrown ethers, lariat-crown ethers, cryptands, spherands, and bridged spherands and wherein said complexing agent is capable of forming in the gasoline a gasoline-soluble complex with an inorganic alkali metal salt and/or the alkali metal cation thereof.