Measurements of excess molar enthalpies at the temperature 298.15 K in a flow microcalorimeter are reported for the two ternary mixtures x(1)C(5)H(12)O + x(2)(CH3)(2)CHCH2CH2CH3 + x(3)CH(3)(CH2)(v)CH3, where nu = 8 and 10. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures. (C) 2004 Elsevier Ltd. All rights reserved.