Densities and surface tensions for binary mixtures of 1,2,4-trimethylbenzene and 1,3,5-trimethylbenzene with 1,1-diethoxyethane and 2,2-dimethoxypropane have been measured over the whole concentration range. Measurements were made under normal atmospheric pressure at (298.15, 308.15, and 313.15) K. The experimental data are used to calculate the excess molar volumes and the surface tension deviations, respectively.