Or the pwr button simply changes the shift points (in terms of RPM / load). Holding gears a bit longer under acceleration for an extra 500rpms, for example.
It doesn't even do that on my 4 speed [is it a 442F?] transmission. All it does is delay the torque converter lock-up clutch engagement by 500 revs. The actual gears change at the usual points depending on load and throttle pedal position.
