2017 Toyota Prius PHV – Video

 

To instill more “EV experience” into the Prius Prime, Toyota started with essentially the same planetary gearset and the same two motor/generators, known as MG1 and MG2, down to the part numbers. But with fresh software controls and the use of a one-way sprag clutch, which is like the freewheel on your bicycle, the Prius Prime’s smaller MG1 can be connected with the crankshaft to propel the car in concert with what’s otherwise a Prius’s sole traction motor, the larger MG2.

That new configuration allows the Prius Prime to, finally, shut down the engine to allow driving the car in a pure EV mode. It’s quiet and quick at low speed, you don’t have to worry about juicing the accelerator pedal too much, and it isn’t in any way sluggish at highway speeds.