Asymptotic behavior correlations (ABCs) based on the properties of pure n-paraffins are used to predict the bulk properties of liquid mixtures derived from the Fischer-Tropsch synthesis. Comparisons are made with literature data for congealing point, density, specific heat, viscosity, thermal conductivity, and surface tension. Mixture property predictions are based on appropriate average carbon numbers and on a general property mixing rule. Both ideal and nonideal solution behavior are exhibited. For the nonideal properties, viscosity and surface tension, mixing rules are proposed and parameters regressed to obtain reasonable agreement with mixture data. Property estimates based on the appropriate average carbon number are probably sufficient for most engineering applications. Methods are outlined for estimating different carbon-number averages based on congealing- and melting-point, density, and the Anderson-Schulz-Flory distribution when the carbon number distribution of the mixture is not available. The presence of other Fischer-Tropsch byproducts appears to have little effect on the accuracy of predictions made for high molecular weight mixtures.