In this study, the limit of water dissolved in gasoline was studied. The mixture of pentane, hexane, and cyclohexane were considered to represent the gasoline. In order to investigate the behavior of this tolerance, the liquid-liquid equilibria of three ternary systems: ethanol- water-pentane, ethanol-water-hexane, and ethanol-water- cyclohexane, of three quaternary systems: ethanol-water-pentane-hexane, ethanol-water- pentane-cyclohexane, and ethanol-water-hexane- cyclohexane, and of one quinary system: ethanol-water-pentane-hexane- cyclohexane, were studied. The experiments were conducted at 293.15, 303.15, and 308.15 K. The experimental data were correlated with the UNIQUAC activity model and the interaction parameters of all binary pairs among these compounds were determined. As the results of study, a good correlation was obtained for quinary system with the binary interaction parameters determined in this study.