Densities, viscosities, and refractive indices of the ternary system ethanol + 2-methylpropan-2-ol + 2,2,4-trimethylpentane at T = 298.15 K and the binary systems ethanol + 2-methylpropan-2-ol, ethanol + 2,2,4-trimethylpentane, and 2-methylpropan-2-ol + 2,2,4-trimethylpentane were measured at T = (298.15, 308.15, and 318.15) K and atmospheric pressure over the whole composition range. Densities were determined using a vibrating-tube densimeter. Viscosities were measured with an automatic microviscometer based on the rolling ball principle. Refractive indices were measured using a digital Abbe-type refractometer. Excess molar volumes (V-E), deviations in the viscosity (Delta eta) from the mole fraction average, and deviations in the refractive index (Delta eta(D)) from the volume fraction average for the mixtures were derived from experimental data. The binary and ternary data of VE, Delta eta, and Delta eta(D) were correlated as a function of the mole fraction by using the Redlich-Kister and the Cibulka equations.