My 2020 Ram has a system called etorque that accomplishes something similar but without any extra drive motors. The alternator is a motor/generator and can drive the drive train through the conventional engine. So it never really does it without the engine also running at least at an idle, but it does regen braking, auto start stop, and adds 16hp and 130 ft-lbs of torque. Has a very small battery 48 volt, 430 watt hour. Oh and the whole system adds 90 pounds total
https://www.popularmechanics.com/car...-1500-etorque/