The excess molar enthalpy H-m(E)(x = 0.548) of the {x benzene + (1-x) cyclohexane} mixture was measured near the vapour pressure curve of benzene, and was measured in the intermediate region between the liquid state and the state near the critical points. The contour of H-m(E)(x = 0.548) was created on the p- T plane over a wide range of temperature and pressure including near the critical points. A valley was observed for the H-m(E)(T, p, x = 0.548) surface in the intermediate region between the liquid state and the state near the critical points. The H-m(E)(x = 0.548) smoothly decreased on the high- temperature side of the valley as temperature and pressure increased, and dramatically increased in this region as the temperature and pressure approached the critical points. Near these critical points, the H-m(E)(T, p, x = 0.548) surface had two ridges, which extended the vapour pressure curves of benzene and cyclohexane. Finally, it was observed that near the critical point of benzene, H-m(E)(x = 0.548) reached a local maximum at a temperature and pressure slightly less than the critical point of benzene. (C) 2018 Elsevier Ltd.