A gasoline additive concentrate composition comprises a solvent, an alkoxylated fatty amine, and a partial ester having at least one free hydroxyl group and formed by reacting at least one fatty carboxylic acid and at least one polyhydric alcohol. A fuel composition comprises gasoline and the gasoline additive concentrate composition. A method of operating a gasoline internal combustion engine comprises fueling the engine with the fuel composition and is effective in reducing fuel consumption.