Vapor pressures for mixtures of a hydrocarbon fuel with ethylene glycol dimethyl ether (EGDME) and diethylene glycol dimethyl ether (DEGDME) were measured by comparative ebulliometry with inclined ebulliometers. Experimental data of vapor pressures and equilibrium temperatures for each mixture were correlated by the Antoine equation. The pseudo-binary vapor-liquid equilibrium (VLE) data were calculated with a non-random two liquid (NRTL) model. Prediction of the vapor pressures for the hydrocarbon fuel from the American Petroleum Institute (API) equations gave relatively satisfactory results. Furthermore, thermal conductivities for the pseudo-binary systems were measured at 273.15 and 298.15 K by means of a relative transient calorimeter. The data were compared to those calculated from the Jamieson equation. These results could provide important information on the development of oxygenate-blended fuels.