If you want an efficient 60' with an automatic, most of the magic is in the converter. If you want an efficient 60' with a manual, most of the magic is in what the clutch is doing. In both cases it's not so much about the converter/clutch itself, more about what the converter/clutch allows the...

A little background first, here’s something to think about- if you know an engine’s average steady state torque output over a defined rpm band, as well as it’s rate of full throttle acceleration (without external load) over that same rpm band, you can calculate the approximate torque-seconds...