[dcb]

I am really just saying that there are energy conversion losses from the ICE in a series hybrid that a parallel hybrid does not have to endure, and in the "range extender" mode these will be magnified.

If I needed to take my EV on a long boring range extended hiway trip, I would add a single speed optimized engine to drive a wheel as noted in my first post. it is essentially A parallel setup with a single reduction (and chains can do that at 98%) or a more efficient transmission than in your typical ICE that doesn't mesh unused gears just for convenience. I don't think the transmission options have been totally explored, but they can be minimized like anything else in a fairly predictible manner (old Mech, that is hydraulic bit is TMI, not able to sort that out right now, maybe another thread?)

series gets the hype for convenience of implementation, you do not have to think about driveline issues, but there are real conversion losses which rarely get addressed and are presented as their optimal values when they are. if a motor is 80-90 % efficient, and a generator is 80%-90% you have a worst case of a %64 efficient ICE driveline and a best of .81 for series.

I'm in favor of EV's, the question is what form of "range extender" is better (series or parallel) for maximum efficiency if you assume R&D in both areas and a driver willing to drive (he can also keep the engine near bsfc by hand, with electric regen and accel as additional options now, or a computer can do it).

But really "electric advantages" apply to series and parallel, it essentially cancels out of both sides of the equation IMHO.