Oh yah, I had an old 78 Chevy with a tricked out 400 on it that would get 8 MPG. No matter what you were doing, full empty it was 8 MPG. It had 2 gas tanks so I could get a decent range between fillups but when I did fill up, ugh, there goes a few hours of pay.
Currently I have a 2017 chevy that was getting about 18 MPG empty, about 15 MPG running at 85 to 95 MPH so not complaining too much. WHen towing, wind drag makes a BIG difference but 12 was the worst I ever had with a huge trailer and also one of those with the fold down ramp to drive lawn equipment up, that thing acts like a huge sail catching wind and slowing you down.
I don't think it's overly fair to compare range loss due to aerodynamics OR incorrect loading of your vehicle to range loss due to just the towing period, because aero loss can be greatly mitigated, as can load distribution. Go ahead load up your tongue and that truck will struggle all day. Now load it correctly with most the load over the axle and she runs like a dream.
Ive seen more than one video already where they fucked with loading to try to 'prove' how inferior Electric was at towing. It's like Really? you have to fucking cheat to make your point? go lick the trucks mains dirtbag.
Aaron