One promising direction to enhance the performance of routing protocols in mobile ad-hoc networks is to use GPS location information. Grid-based routing is one type of protocols that use GPS. In this paper, we propose and evaluate a routing protocol called weighted grid routing protocol (WGRP) which combines features from the topology-based and the grid-based routing approaches. WGRP uses a weighted combination of residual energy and node mobility measures to select grid cell heads. To the best of our knowledge such measures are used for the first time in grid environment. WGRP presents an improvement over existing grid-based routing protocols by eliminating the use of periodic control packets and introducing the selection of more stable cell-head nodes. Simulation results show that WGRP outperforms the famous ad-hoc on-demand distance vector (AODV) protocol in terms of path stability and reduced routing overhead.