Friction theory is coupled with statistical associating fluid theory, SAFT1 and PC-SAFT, to predict the viscosity of mixtures. The universal friction theory parameters working with SAFT1 and PC-SAFT for pure n-alkanes, which were previously found to scale linearly with molecular weight, are used without any readjustment to predict the viscosity of symmetric and asymmetric mixtures of n-alkanes with accuracy that is adequate for engineering purposes.