Oxygenated fuels are of great interest as these are more energy efficient and environment friendly. Therefore, thermodynamic properties like density, ultrasonic speed and refractive indices of diisopropyl ether+benzene+nhexane mixtures were measured experimentally at 298.15 K, 308.15 K and 318.15 K. Excess properties like volume (Vm E ), isentropic compressibility (KS E), intermolecular free length (Lf E) as well as deviation in ultrasonic speed (Δu) and refractive index (Δn) of these mixtures were derived from experimental data. The Vm E values were also fitted to the Singh, Cibulka and Nagata equations, and the same were also predicted using Prigogine-Flory-Patterson theory and four geometrical models from constituent binary Vm E data. The u data were correlated by Nomato, van Dael, impedance dependence correlations and CFT theory at 298.15 K. Lf E and Va E were also calculated using Jacobson free length theory at 298.15 K. The n data were also predicted by Arago-Biot, Gladstone-Dale, Weiner, Heller, Newton, Eyring and John mixing rules.