Excess molar enthalpies, H-m(E), densities, rho, and excess molar volumes, V-m(E), of dimethyl carbonate or diethyl carbonate + 2,2,4-trimethylpentane have been determined at 288.15, 298.15 and 313.15 K and at atmospheric pressure, using an LKB flow microcalorimeter and an Anton Paar digital density meter. For all mixtures, the H-m(E) and V-m(E) values are positive and increase slowly as the temperature is increased. The experimental values have been correlated by the Redlich-Kister equation and the adjustable parameters have been evaluated by least-squares analysis. The results are discussed qualitatively in terms of molecular interactions and have been interpreted by an extended cell model.