The (vapour + liquid) equilibria of (3-methylpentane + heptane) at T = 308.15 K, 318.15 K, and 328.15 K; of (3-methylpentane + octane) at T = 338.15 K; and of (toluene + octane) at T = 333.15 K, have been obtained by using a dynamic still, and excess volumes of these mixtures have been measured at T = 298.15 K using an Anton-Paar densitometer. The VLE results were analysed by applying the maximum-likelihood principle and are well correlated by the Wilson, NRTL, and modified UNIQUAC equations. They are also compared satisfactorily with a group-contribution equation of state.