The initial automatic transmission to utilize a torque converter (as an alternative to a fluid coupling) was the Buick Dynaflow, which was introduced for the 1948 model year. In ordinary driving, the Dynaflow utilised only the best gear, depending on the torque multiplication of the torque convertor at reduce speeds. https://milougqah.blogozz.com/32937122/the-fact-about-gearbox-auto-that-no-one-is-suggesting