Gas-expanded liquids have received significant interest as catalytic reaction media. While most GXL studies involve CO2 as the expansion gas, there is growing interest in non-CO2 based GXLs, especially when the expansion gas is also a reactant. In this work, we focus on ethylene as an expansion gas, motivated by recent experimental studies on the catalytic epoxidation of ethylene using ethylene expanded methanol/H2O2/water mixtures within metal doped silica mesopores. Reported simulation studies on GXLs, even for bulk properties, have been primarily limited to single-component or binary systems. Here we extend the use of simulation to the study of a bulk ternary GXL system - namely, ethylene-expanded mixtures of methanol and water mixtures. We investigate the phase behavior and transport properties in the liquid phase with respect to temperature, pressure and water content. The model force fields are validated by comparing compositions and transport properties to existing experiments. In addition, we study local liquid solvation structure as a function of composition. (C) 2016 Elsevier B.V. All rights reserved.