To counter this effect, some automobiles Use a torque converter which has a lockup clutch. If the two halves of the torque converter get up to speed, this clutch locks them collectively, making sure which the engine and gearbox spin at precisely the same velocity and reducing electrical power loss. https://torque-converter-clutch20616.tribunablog.com/not-known-facts-about-torque-converter-clutch-48602765