The very first automatic transmission to use a torque converter (instead of a fluid coupling) was the Buick Dynaflow, which was introduced with the 1948 product year. In standard driving, the Dynaflow employed just the top rated gear, counting on the torque multiplication from the torque convertor at lower speeds. https://gearbox-auto10639.ambien-blog.com/40603535/details-fiction-and-gearbox-auto