Speed of sound, density, and isentropic compressibility have been measured over the entire composition range at atmospheric pressure for the system methanol + tetraethylene glycol dimethyl ether (2,5,8,11,14-pentaoxapentadecane) at five temperatures from 293.15 K to 333.15 K. The values of these magnitudes were fitted by a polynomial equation in mole fraction. The values of the densities and isentropic compressibilities have been used to calculate excess molar volumes and isentropic compressibility increments, respectively, for the mixing process. These results have been fitted to a variable-degree polynomial equation to obtain the correlation parameters together with the root-mean-square deviations between the experimental and calculated values.