The excess enthalpies at 298.15 and 308.15 K for six binary mixtures of acetonitrile + C-8 aliphatic ether {heptyl methyl ether (CH3OC7H15)-C-n, or ethylhexyl ether (C2H5OC6H13)-C-n, or pentyl propyl ether (C3H7OC5H11)-C-n-C-n, or isopentyl propyl ether (C3H7Oi)-C-n C5H11, or dibutyl ether (C4H9OC4H9)-C-n-C-n, or butyl isobutyl ether (C4H9OC4H9)-C-n-C-i} have been determined by isothermal titration calorimetry using the TA Instruments (model TAM III) calorimeter. The possibility of the COSMO-SAC model to account for the thermodynamic differences between these systems has been tested.