During the thermo-mechanical modeling of the friction stir welding (FSW) process, usually higher output temperature (NT11 or TEMPMAVG) is predicted using the coupled Eulerian-Lagrangian (CEL) formulation (where the workpiece modeled as Eulerian) available in ABAQUS software. Whereas a relatively lower output temperature (for almost same parameter) is obtained when modeled using the pure Lagrangian formulation (available in DEFORM-3D software). What are the prime reasons affecting this output?