S (stall position): During this issue the turbine speed is zero plus the impeller is rotating; the efficiency while in the stall stage is minimal, all-around 50%, which suggests that half of the power coming in the engine is misplaced as a result of friction and dissipated as heat; at https://deanlmlkl.blogolize.com/5-tips-about-torque-converter-clutch-you-can-use-today-73033595