Most of the 154 ton truch fleets that were predominant in large surface mines in the 1970s and 1980s are approaching the end of their economic life. One replacement option considered by mine operators is a change to the 218 ton trucks. A comparison of load capacities between the 154 ton and the 218 ton trucks indicates a large productivity advantage in favor of the 218 ton trucks. This advantage, however, is often reduced by a number of onsite-specific factors. Therefore, a careful evaluation is required to define the actual benefit of changing to the larger trucks. This article discusses some important factors that have an impact on the truck size selection.