1-component Extended Hard-Sphere (1-cEHS) model has been developed recently to predict the viscosity of liquid, n-alkane mixtures. It represents a mixture by a single pseudo-component characterized by an appropriate molecular weight and calculates the viscosity by means of the modified, extended hard-sphere model (EHS) that makes use of a universal function relating reduced viscosity to reduced volume. In this work we have extended the model to also predict the viscosity of mixtures containing alkylbenzene and cycloalkane species. Furthermore, we have developed a new 3-component Extended Hard-Sphere (3-cEHS) model which requires only a knowledge of the overall composition of n-alkane, alkylbenzene and cycloalkane species. Extensive comparison with the available experimental data indicates that both models (1-cEHS and 3-cEHS) predict the viscosity of binary and multicomponent mixtures containing n-alkane, alkylbenzene and cycloalkane species with uncertainty of 5–10%. The proposed models are a precursor of a new family of models that do not require a knowledge of the detailed composition of the mixture, but still take advantage of the underlying molecular description.