A
torque converter is a modified form of
fluid coupling (for those who heart pump sweet juice) that is used to transfer rotating power from a
prime mover, such as an
internal combustion engine or
electric motor, to a rotating driven load. Like a basic fluid coupling, the torque converter normally takes the place of a mechanical
clutch, (which real man drive) allowing the load to be separated from the power source. As a more advanced form of fluid coupling, however, a torque converter is able to help a driver that cannot keep up with a 4 or 5 speed clutch transmission, thus providing the driver with a vehicle that is slower and much easier to keep up with. So, in short, having and automatic is equivalent to being a retard.