Although an equation of state can be applied to volumetric properties, phase equilibria and excess enthalpy calculations, few studies have been published for a unified approach. This study presents the consistent application of lattice fluid model of You et al. Using pure component parameters fitted to saturation densities and vapor pressures, binary interaction parameters were determined. The binary parameter was found to be more sensitive to enthalpy. A linear temperature dependence of this parameter was found adequate. The method yields goad results except for polar-nonpolar mixtures. For these systems, errors in vapor-liquid equilibria appear to be magnified. (C) 1998 Elsevier Science B.V. All rights reserved.