Cooling system air flow resistance characteristics are different for commercial and military combat/tactical vehicles. The optimum configurations of air-cooled heat exchangers in these vehicles are therefore different. In this paper, the unique characteristics of the cooling air flow path of military combat/tactical vehicle are presented. Optimization analysis of liquid-to-air heat exchanger considering the minimum fan power requirement as design criterion are discussed. An exchanger with smaller face area and thicker core, which was previously thought to be undesirable, is found to be favorable for some typical applications.