The 1st automatic transmission to use a torque converter (as opposed to a fluid coupling) was the Buick Dynaflow, which was launched for that 1948 product calendar year. In ordinary driving, the Dynaflow utilized only the best gear, counting on the torque multiplication on the torque convertor at decreased speeds. https://gearbox-auto97405.aioblogs.com/87152854/5-tips-about-gearbox-auto-you-can-use-today