towing capcity and payload capacity.

Not sure OP if truck your looking at is a 4x4 (but will assume it is being your in WI), so it will weigh in the hood of 8500 lbs. That only leaves you with 1500 lbs of "X" wether it be cargo, people or trailer. If you have 4 people at 150# each, that's 600#, now your down to 900# capacity leftover for "X".

Not that this will help you any, but I had a '03 F250 cc,4x4,6.0 PS, 50 gallon Transferflow tank and it came in at 8700. Always thought that I'd never use up all the trucks capacity. Bought a '06 Cedar Creek Silverback 33LBHTS (dry wt 10,800, Max GVW 13,800, pin 1800) being a newbie, figured....no problem. Hooked up, fully loaded, I had 10,800 on the truck (truck's GVW was 8800). Yes I was over big time, and truck did tow it just fine. But always had to be in the mindset of keeping a safe distance from one in front of me. Said that next truck will be a 350 ( alot of that info came from reading a lot of posts on here).

So bought a '15 F350 cc,4x4,6.7, srw. Did an awesome job of towing same trailer. Winter of '16/'17 we decided to get serious about a new coach and ending up getting a '18 Big Country. Well now back in same boat w/ this truck & RV as we were wih the '03 F250 and '06 RV. The '15 did a great job towing the BC, but again, I was at or over on some of the trucks capacities. RV had a dry wt of 14K, max GVW of 16K, pin of 2900. Fully loaded, I was over on truck's GVW of 11,500, rear axle and tires. Overall, didn't really bother me. Come vaykay planning for 2018 and now the weights are bothering me cuz the compass had us going to FL during the summer. Traded in the '15 for a '17 F350 cc,6.7,4x4 dually and all I can say is it made a world of difference! DW even liked driving it better than the srw towing. Yes, I DO mis my srw, but for towing the BC, the dually wins.

So bottom line is, I think I'd pass on the 250 and look for a 350 srw and then keep a 5th wheel under 15k GVW. If your towing a TT, then the 250 will probly be ok, but not a 5er. Just my $.02

With either truck keep in mind when you’re not loaded you really do need 80psi in the rears. Inflate to 45-50 and a lot of the buckboard ride will disappear.

Payload is determined by the class of truck you have.. A 250/2500 truck can really only have a #10,000 GVWR.. Go to the 350/3500 truck and it can go to #11,500 and maybe more if a dually?

Drive train wise, there really is no difference..

Heck, I have a "max tow" F150 with #7700 GVWR... But, for the most part, it's just a GVWR package that gets me #500 more GVWR than a regular tow F150.. No suspension, brake or frame difference... I just pay more for my registration every year compared to a #7200 GVWR F150.

Basically the same thing with the HD trucks too.

Back only a decade or so ago, 25 series trucks only had #8000 GVWR and 35 series had #10,000..

So, it's all relative and what you pay for your trucks registration depending on the state you live in.

Good luck!

Mitch

Payload is also an issue with gasoline powered trucks, just not as much because gasoline engines weigh less than diesel engines.

Welcome to the forum! A 2015 F250 will do the same job as a 2015 F350 SRW. They are the same truck with different class rated GVWR. The 250/350 diesels generally have the same tires/wheels and axle. Some 250 models, even the same springs. In any case, if you have found a nice 2015 250, it will easily work for the size FW you are talking about. If you need more truck, due to getting a large FW, a 350 DRW will be required, rather than a 350 SRW.

Jerry

yup, TV mfg assume 10% tongue weight, 20%? pin weight

Trailers are generally above 10%, closer to 15% tongue weight
5th wheels 25% or more pin weight

so, a big contradiction at the start. I'm towing a 9,500lb TT, tongue weight 1400, DW and stuff in the bed and I'm right at GVWR for the truck, 10K,

Now that preliminary data shows 2020 GM 2500's are class 3 and are at 11,500 ish, they are finally addressing some of the GVWR issues with cc 4x4 diesels. Maybe Dodge and Ford will follow suite.

It's really a "which weight class" game for the mfg.

The chart says 15 - 16 K depending on regular or 4 by 4 for fifth wheels. From years of reading this forum, likely your pin weight will determine the weight of the rig rather than the towing capacity.

Nobody ever said you have too much truck.

You are correct, with an RV trailer putting such a high percentage of weight on the truck axles you normally run out of payload long before towing capacity. It would be different if you were towing a boat or a flatbed trailer loaded with lumber.
2 series trucks with lots of options and diesel engines have very little payload left over. You will be better of with a 3 series truck. The ride will likely be no different. Depending on option packages the F250 may be nearly identical mechanically to the F350 but with a GVWR not over 10,000 pounds to dodge various DOT regulations.
If your one of those people who thinks the world will end if you go over GVWR then get the F350.