Hey, as my first post, I can give you a little info about towing an RPod without an air conditioner and with two different v/6 engines. We bought our RP175 about 3 months ago. It did not come with air, and we're saving up to have one installed--not a Dometic from all the feedback I've read. We live in western Washington state, and except for the I-5 corridor, you pretty much have to tow either foothills or passes to get anywhere around here.
The Rpod is our 5th trailer. All have been between 17 and 22 feet long. We've towed with v/6es and v/8s, with and without sway and WDH. We're towing the RPod without either sway or WDH, and it follows nicely. Our last trailer was an 18' Chalet (folding slab side). It weighed a few hundred pounds less than the 175 at 2700 lbs. with a 300 lb. hitch weight. We towed it with an F150 v/8 (13mpg.) and a Dodge Dakota v/6 (tow pack with auto, 3.92 rear end and a 4800 lb. tow capacity). The Dakota got about 13 to 14 mpg towing the Chalet.
We thought the Dakota was a good fit for the RPod. We were very wrong. The added wind drag from the RPod really blitzed the mileage and accentuated the fact that the 3.7 v/6 in the Dakota really didn't have enough hp and torque to tow well in the situations we would have to nearly always drive in around here.
The mileage dropped to between 9 and 11 mpg. and the 3.7 really labored on hills. The fact that the Dakota had a 4 speed auto with 4th locked out in tow/haul really caused some severe reving of the engine to maintain speed. Traveling on the flat was fine, but still only 11 mpg.
We have plans to replicate a trip we took about 20 years ago--towing I 90 from here to South Dakota. So much neat stuff to see! It would have been pretty tedious towing the 175 with the Dodge Dakota, so it was either get another full size truck or a v/6 with more suds. For various reasons, I zeroed in on either a used Nissan or Toyota p/u.
We found a nice 06 Toyota Tacoma with the tow pack (6500 lbs. tow capacity). We did the exact same trip with the Tacoma that garnered us 9 mpg with the Dakota. We got 12 mpg, never went below 3rd gear and accelerated well enough to catch a couple diesel pushers on some hills.
It would be nice to get a little better mileage, but any time you tow a rig that pushes wind, your mileage is not gonna be good. The same F150 that got 13 mpg for me towing the folding Chalet would get as low as 8 mpg when we had the 22 foot slabside.