A motor/generator/transmission system includes: an axle; a stator ring having a plurality of stator coils disposed around the periphery of the stator ring, wherein each phase of the plurality of stator coils includes a respective set of multiple parallel non-twisted wires separated at the center tap with electronic switches for connecting the parallel non-twisted wires of each phase of the stator coils all in series, all in parallel, or in a combination of series and parallel; a rotor support structure coupled to the axle; a first rotor ring and a second rotor ring each having an axis of rotation coincident with the axis of rotation of the axle, at least one of the first rotor ring or the second rotor ring being slidably coupled to the rotor support structure and configured to translate along the rotor support structure in a first axial direction or in a second axial direction.