In wireless ad hoc networking efficient resource management is crucial in order to deal with delay sensitive traffic. This paper presents results from studying such traffic in a mobile scenario and focuses on the gains that can be obtained by variable data rate. We study this from several points of view, the effect of lower data rates, the routing metric, and delayed routing update. The results show that the greatest benefit with adding lower data rate links is the increased connectivity in the network. Lower data rates also gives a better support when the routing information in the network is delayed. Further, the choice of routing metric is also important in order to be able to fully utilise a large range of data rates.