Performance Evaluation of Energy Efficient On-demand Routing Algorithms for MANET Mobile ad hoc networks are a class of dynamic networks without any centralized administration. A major bottleneck in mobile ad hoc networks (MANETs) is the energy consumption since nodes are usually mobile and battery operated. To maximize the lifetime of mobile ad hoc networks (i.e., the lifetime of the nodes themselves) the power depletion of network must be evenly distributed, i.e., there must be a uniform drain of energy from the nodes, and the overall transmission power requirement for each connection request must be minimized. This paper proposes two algorithms called energy efficient delay time routing (EEDTR) and maximised energy efficient routing (MEER), which try to increase the operational lifetime of mobile ad hoc networks. These algorithms are modified versions of the existing dynamic source routing (DSR) algorithm. These algorithms select fully distributed routes, thus balancing power consumption of the entire network. The first algorithm(EEDTR) introduces a delay in forwarding the packets by nodes, which is inversely proportional to the remaining energy level of the node. The second algorithm includes energy information on the route request packet and select the routes based on this information (MEER). These algorithms are designed and implemented using global mobile simulator (GloMoSim), a scalable, simulation environment for network simulation. Based on the results obtained, this paper concludes that the proposed algorithms increase the lifetime of mobile ad hoc networks, at the expense of end to end delay and control overhead.