Energy efficiency is an important aspect in wireless sensor networks. WSNs support a clustering-based routing protocol called Lower Energy Adaptive Clustering Hierarchy (LEACH) Protocol which uses hierarchical clustering to solve the energy consumption issue. The New Improved LEACH protocol combines LEACH and MD protocols. It allows the clusterhead (CH) to be in a sleep mode if there is no data to be sent, this is a contrast to the LEACH protocol which assumes that the CH is always switched on. In previous work, this approach was evaluated using mathematical model. The proposed protocol uses simulation model. The simulation tool we used for the purpose is MATLAB (version 7.10). Simulation results show that the New Improved LEACH routing protocol reduces energy consumption and increases the total lifetime of the WSN compared to the LEACH protocol.