The Tesla Model X managed 235 miles on a single charge while towing a Bowlus Terra Firma.
www.autoweek.com
235 miles on a charge with a 3200 lb 26 foot trailer.
First, I trust the Bowlus marketing department about as far as I could throw one of their $300k trailers. That said, you're still comparing apples to oranges. The Bowlus is less than half the weight of the Edmunds trailer, with almost certainly less than half the drag. Aero drag is a function of Cd and cross sectional area. The Bowlus is about the same height, but only 80" wide (vs. 96" for Edmunds). That's 20% less frontal right there, then the semi-circular-ish cross section shaves off another 14% for 34% total reduction. The boattail dramatically reduces Cd, at least 20% but could be easily be 30-40%. That's why eco-modders put those long boattails on their Honda Civics and such.
Towing a camper with an electric SUV may be the ultimate test of any fast-charger network. And, for one couple at least, Tesla has passed. “We were like pioneers in a Conestoga wagon,” says Fred Hooper, a Pennsylvanian veterinarian who, with his wife Jenny, just returned from a 7,700 mile...
www.greencarreports.com
3800 lb trailer, "had to find a charger every 200 miles" with consumption ranging from 600-1200 wh per mile
R-Pod 180 isn't 3800 lb, I've looked at them to tow behind my minivan. Dry weight is a bit over 2900. And the 180 is even 2" narrower than the Bowlus. Anyway, 200 miles is the author's invention, inconsistent with what the owners actually said:
"Jenny reports that the trailer cut the range of their Model X by 45 to 60 percent depending on hills and wind".
X is rated at 348 miles, but real world more like 300. So that's 120-165 miles. 600-1200 Wh/mile comes to 83-166 miles, on an unrealistic 100-0% leg.
They also told the author they'd drive "a couple hours" before breakfast, then eat while charging, then drive "a couple more hours" and stop for lunch. That's 110-120 miles per leg. She said charging added 50% to their travel times, again consistent with one hour charging for every two driving.
This trailer has similar frontal area as Edmunds, though much lighter. Their X showed 347 miles of range at the start. They easily made the 97 mile outbound leg thank to a tailwind. Could have gone 130. But on the return trip they had to slow to 53 mph to make it back at all. So out-and-back average is 115 miles using the full 100-to-0% SOC. So realistic legs of 70-100 miles. Reduce that another 10-15% for the heavier Edmunds trailer.
Towing efficiency is all about the trailer. The tow vehicle is pretty irrelevant. The same Edmunds F-150 Lightning got 50% more range in an earlier test towing a flatbed with a car on it. Worse Cd, but less weight and much lower frontal area. And I'm sure it'd do even better towing the lightweight Bowlus airplane fuselage.
Put the Model X in that Edmunds test and it'd do 60-80 mile legs, with ~100 miles as the no-wind, flat terrain 100-to-0% maximum best case.