Infinite-pressure mixing rules and zero-pressure mixing rules are related by a very simple equation. The zero-pressure models and the infinite-pressure models are interchangeable through this connection. This paper will show how to convert the Huron-Vidal infinite-pressure mixing rule to a zero-pressure mixing rule, or vice versa. The MHV1 zero-pressure mixing rule will be reformulated to satisfy second virial coefficient constraint. The Twu-Coon and Wong-Sandler infinite-pressure mixing rules will be modified to improve their accuracy for reproducing the incorporated G(E) model. A simplification of the Twu-Coon-Bluck [TCB(r)] zero-pressure mixing rule will be presented. The MHV1 mixing rule will be shown to be a special case of TCB(r). (C) 1998 Elsevier Science B.V. All rights reserved.