
07/07/2025
Why hasn't Nissan brought their e-Power hybrid system to the USA yet? Because they think it's not a "good fit" and the related Mitsubishi Outlander demonstrates why. This non-hybrid Outlander got 30.3 MPG on our test loop, beating the 27 MPG EPA combined score. The long-term Outlander PHEV we owned got just 25.6 MPG on the same cycle. What gives? Well, both the Mitsubishi PHEV and the Nissan e-Power systems are serial hybrids at their core. What does that mean?
In a serial hybrid, an engine drives a generator, then the generator powers a motor that drives the wheels. (Yes there is more going on, but that's the basic layout.) In a parallel hybrid like a RAV4 or Tucson hybrid, the engine and motor/generators work in parallel to power the wheels, so in steady-state travel, the majority of the power is *mechanically* flowing from engine to wheels, which reduces loss. According to a conversation I had with some hybrid engineers, the energy loss in a serial hybrid can be as much as 20%. This is why Honda's 2-motor system, and the Mitsubishi PHEV, have a mode that allows a single fixed gear ratio to be used at moderate highway speeds to help out. The issue with e-Power (and any supposed "range extender") is that it lacks this fixed ratio mode.
So in a nutshell, why don't we have more EVs with "range extenders"? Because the efficiency tradeoff seems to be too much for most car companies to consider.