Agree completely, though I remain hopeful — with one exception.
We can extrapolate valuable data from Ford’s F-53 chassis, as example, and see that very large (wide and tall) motorhomes weighing up to 26,000-pound GVWR and 30,000-pound GCWR are powered by 7.3L V8 with 335 peak HP and 468 lb-ft of torque. I would roughly compare that with a Super Duty towing a large non aerodynamic heavy trailer at highway speeds, which is where limitations of an extended-range generator apply more directly.
Most owners know and accept that when towing a large fully-loaded trailer, as is the case with heavy motorhome that operates near max load 100% of time, that performance will be lower than normal, and fuel consumption quite a bit higher. For example, a large Class A motorhome cruising at 70 MPH may only average 7 MPG, so burns 10 gallons per hour. Thai’s roughly 150 HP at engine “on average”. To me the concept of an EREV Super Duty seems viable from a power standpoint. It would seem a large-displacement Atkinson V8 should be able to produce enough power to support highway cruising for hours at a time.
The problem I still see is that even with Atkinson engine lower brake specific fuel consumption, generating electricity to power electric motors is far from 100% efficient, and may result in unacceptable highway towing MPG. A driveshaft connecting an engine to a differential is pretty damn efficient by comparison. Very low tech but quite effective nonetheless.
In a heavier vehicle, regen braking adds up to a lot of savings in both fuel and brake maintenance. Using a battery that’s much smaller than used in a BEV will also reduce long term replacement cost. V8 driving a generator at relatively constant load is probably better for life so long as regularly serviced.
No tranny, no driveshaft, no transfer case, no differential. It’s a lot simpler and should be more durable. And it won’t run all the time. May only be needed intermittently.
So out of curiosity, how durable long term would this sort of powertrain setup be? It seems quite complex. I could see that being off-putting to super duty owners who routinely put their trucks through intense abuse and expect them to work flawlessly. Is this sort of thing more or less reliable than a conventional hybrid?