I think this was said but not discussed. Does not the automatic transmission go into a solid or locked up connection at a certain speed? I have a PDF file describing the 4EAT which mentions lock up frequently:
Essentially every auto trans locks up completely at cruise. That lockup is accomplished using fluid pressure, which is developed by a pump in the transmission, which takes power to operate. Likewise, there are valves and solenoids in the auto trans which are activated at all times to keep the transmission in gear, to keep clutches tight, etc. These take either fluid pressure or electricity to operate, and that fluid pressure or electricity uses engine power to generate. The stick has a clutch pressure plate which is locked up via spring pressure, not hydraulic power, so you are down to gear friction only... The "little man" making the automatic transmission shift and holding it in gear needs to be fed...are you with me there?
Quick edit--note also that an auto trans will have a trans cooler in the radiator, and maybe an external cooler as well. The fact that this cooler is there means that heat is being generated via additional friction from additional moving parts, including the pump. And this extra heat energy is dissipated into the atmosphere....so automatic transmissions contribute to the global warming problem more than manuals too
CVT's are theoretically very efficient as well, but as a real world example, the Nissan Versa was available with both a CVT and a 4-speed traditional automatic transmission. The EPA mileage was better with the CVT, but in real world magazine tests, the 4-speed auto generally achieved better mileage because the CVT requires a whole bunch of fluid pressure to keep the belt/chain tight in the cones. CVT gearing is SUPER efficient, but the operation of the CVT takes a whole bunch of fluid pressure.
An automatic can be programmed to "shift for mileage" so if the shift patterns offset some of the inefficiency of the basic operation, it *could* get better mileage than a stick in dynamic driving situations. But if we confine the example to a 60 mph freeway cruise in top gear, with equal gear ratios, the stick will always be better than the automatic--even your little quotes talk about solenoids and pressure--these suck power. Difference may be small, but there is a difference. Again, as I said in the earlier thread, manufacturers are moving to electric power steering instead of hydraulic for the same reason. When you are not turning the steering wheel, the hydraulic PS is still using power to pressurize fluid, just like the auto trans.