A good cache management method for mobile wireless environments has to handle problems associated with limited client resources and frequent client disconnections, in addition to standard problems found in wired environments, such as variable data sizes and data updates. In this paper we propose a gain-based cache replacement policy, Min-SAUD, for wireless data dissemination when cache consistency must be enforced before a cached item is used. Min-SAUD considers several factors that affect cache performance, namely access probability, update frequency, data size, retrieval delay, and cache validation cost. Min-SAUD is optimal in terms of the stretch performance measure. Preliminary experimental results show that in most cases the Min-SAUD replacement policy substantially outperforms two existing policies, namely LRU and SAIU.