| abstract |
The present invention is directed to a method to clean up or keep clean the fuel system of a direct injection spark-ignited engine by operating the engine with a fuel composition that includes a liquid fuel and a fuel additive composition.The fuel additive composition useful in the present invention has at least one nitrogen-containing dispersant and optionally a fluidizer where the dispersant has a specific lipophilic parameter and the dispersant or the dispersant and the fluidizer have a specific hydrophilic-lipophilic parameter, the dispersant provides about 0.15 to about 50 ppm by weight nitrogen in the fuel composition, and the fluidizer and/or the dispersant provide about 10 to about 10,000 ppm by weight active components.The method of the present invention is effective in controlling deposits in fuel injectors and combustion chambers of a direct injection spark-ignited engine. |