Originally Posted by eBEEMER
I have also been told that regenerative breaking will not work with an automatic box.
I understand that auto gearboxes are less efficient than manuals, but can't find any reliable info on how less efficient.
Like on KansasEV design, if there's no torque converter, regen will work. And if there were TC, regen would work if there TCC is locked (TCC = torque converter clutch).
Without TC, automatic is as efficient as the manual, because it's the slippage of the TC that makes autos less efficient. But that depends on make and model and how the automatic is controlled. Old school autos are less efficient than modern ECU controlled ones.