To counter this effect, some vehicles Use a torque converter which has a lockup clutch. In the event the two halves of the torque converter get up to speed, this clutch locks them collectively, making certain the motor and gearbox spin at the exact same velocity and reducing power decline. https://felixubeed.ageeksblog.com/33123083/5-simple-statements-about-torque-converter-clutch-explained