The advantage of the torque converter is the flexible connection of the engine with the car driveline and excellent damping of vibrations and torsional pulses. The car can run at arbitrarily low speed in any gear without fear, that the engine will stop. The disadvantage of the torque converter is constant slippage, which results in higher fuel consumption than when using a conventional friction clutch. Otherwise, to allow the transmission to be changed in the normal gearbox, an additional friction clutch must be used, disengaged during shift periods, or a gearbox with planetary gears (planetary) ,that can be switched under load.