Ordering new Ram and Northstar 12 STC

[Poodlemaster]

Would love some advice on a couple of things before dropping considerable $ on new truck and camper. Had a 16 RAM 3500 diesel dually with upper/lower stable loads and Lance 1172. Worked fine, but will probably need bags with new Northstar since adding a rear super hitch and motorcycle this time. Would you go with the factory air assist suspension on a new 18 RAM 3500 drw or go with full leaf suspension, add stableloads and aftermarket bags? And, I had 3.73 gearing on my 16 that worked fine and averaged around 12-13 mpg with the lance. Another member on here with a 12 STC and 14 RAM has the 4.10 and is getting 13mpg average. I will be loaded with camper full time, so will there be any mpg benefit to the 3.73? If not, I'd rather have the acceleration of the 4.10's. Will be driving cross country twice a year and averaging about 30K miles per year. Lastly, I've been back and forth on the 18 Ram 3500 or a 18 F450 for the tighter turning radius of 450, the 4.30 gearing is the only thing keeping me away, as I don't want to get less than 10mpg with all my mileage. Anyone with the 450 who can comment on mpg loaded full time with approx 5K lbs?

[thedavidzoo]

Since we are the only ones on this forum with a 2014 Ram and the STC, I think, you must be talking about our rig.

Just wanted to give you an updated MPG number. This past summer we did the AK/Canada trip from VA, ~13500 miles. We were FULLY loaded with 4 people for 64 days, usually carrying 5-10 gal extra diesel, so no light weight trip.
My hand calculated MPG overall was 11.75. Now this included lots of 75mph into a strong headwind(thanks ND where we were getting around 9mpg) and well over 1000 miles of 5-30mph gravel roads and frost heave accel/decel. The best we saw was a stretch at 12.42 MPG.
Also around ~866 MPG of DEF. So, more reasonable driving conditions and lighter weights might get you a much better MPG.
I have all STC and stuff weights, and mileage numbers in spreadsheets if interested.

[burningman]

You’ll dump what was still an almost brand new truck/camper setup and buy another new setup for well over $100k but a couple MPG is the deciding factor?
I mean, we all decide for ourselves what we want to do but the math there doesn’t add up.
I’d go with the one you like better. That wide front axle on the F450 and the turn radius would seem to make it pretty attractive for a big camper, and I’m even a Cummins fan saying that.