Jump to content

Towing Capacity


Darin Kent

Recommended Posts

I have a 2015 short bed F350 single axle.  Looking to buy a 5th wheel UVW of 10,570 and GVWR of 13,996.  Ford towing guide shows 15,700lb capacity.   King Pin Wgt of 2,090.  Am I too close to capacity and will my truck struggle?  It is the 6.7L Diesel.  3.55 axle ratio.  Should I get air bags as well?  

Also, is there much difference in towing a 35' 6" vs. 38' trailer?  Should I get an automatic sliding hitch or a manual slider?  

 

New to 5th wheel trailering.... 

 

Link to comment
Share on other sites

You're right on the edge of what I would consider an "ideal" tow package, but you should be perfectly fine. It's going to struggle a "little" on some of the steeper grades, but nothing outrageous if you just watch your temps. My only concern would be your short bed. With a reduced wheelbase that's going to impact your stability to some degree. If you have some tow experience already, I wouldn't be terribly concerned. Or rather.. not worth investing in a new TV over.

Bags? Again... you're right on the borderline. Personally, I would. Better to have them than not. If this is an occassional get-a-way setup then I would be less concerned about not having air bags. If it's a fulltimer tow package I most definately would.

Slider? I would stay with a manual. They weight less and more 5'ers are "short box friendly" these days so it's likely you probably won't even need to use it much. I say save the bucks and the weight. It will also be MUCH easier to remove if need be.

Ideally, I would prefer a DRW long box. I'm the type to always error on the side of safety and stability, but I would be perfectly comfortable with the tow package you're suggesting.

Link to comment
Share on other sites

A 6.7L will have all the power you need, flatland or mountains.  I'd be very careful of the pin weight.  Forget the UVW and use the 14K GVWR of the fifth wheel.  The pin weight can be 20% so that would be 2800 pounds.  Add that to the hitch weight and what ever else you'll have in the trucks bed and check it's payload capacity.  You can easily be over 3K pounds in the bed.  My 2 cents would be a Dually long box for safety margin and possible future growth.

Our 17K fifth wheel has a pin weight of 3800 pounds.....over 22% of the RV weight.  Be leery of the manufacturers pin weight specs. 

Airbags......they can be easily added if needed after you try towing without them.

I wouldn't be concerned about the trailer length, be concerned about it's weight and especially REAL pin weight plus whatever else is in the truck bed.

Greg & Judy Bahnmiller
Class of 2007
2014 F350
2007 HitchHiker Champagne

Both sold 2/19, settled in Foley, AL after 12 years on the road

http://bahnmilleradventure.blogspot.com/

Link to comment
Share on other sites

Pin weight can be between 20 and 25 percent for a 5th=wheel.  A tow behind is only 10 percent.  That is why the tow guides have heavier tor-behind trailer capacities than fifth-wheels.

A 14K trailer can easily have a 3500 lb pin weight and added to the typical weigh of a diesel pickup and you will be exceeding the rear axle capacity, especially with single tires which a short bed has.

 

Please click for Emails instead of PM
Mark & Dale
Joey - 2016 Bounder 33C Tige - 2006 40' Travel Supreme
Sparky III - 2021 Mustang Mach-e, off the the Road since 2019
Useful HDT Truck, Trailer, and Full-timing Info at
www.dmbruss.com

Link to comment
Share on other sites

2 hours ago, Mark and Dale Bruss said:

That is why the tow guides have heavier tor-behind trailer capacities than fifth-wheels.

From my experience, it's generally the exact opposite. You'll have heavier tow capacities with a 5th wheel/goosneck than you will under conventional/hitch tow.

You DO want to keep an eye on your axle weight ratings, and it's generally the GVWR or GCVW that can be limiting factors.

The OP's 5th Wheel cap (F350 SRW 4X4 Crew cab 6.7PSD) is 15.7k. Conventional tow is only 14k.

Ie., GCVW is 23.5k. So with a 14k 5'er and around an 8.5k rig (UCW + Fuel + hitch + gear allowance) he's rolling at around 22.5k. 1k shy of cap even though by his tow rating he should still have 1.7k available. But still good to go.

For him, I would think the GVWR will be the limiting factor. He's 6.6k UCW w/7k CCC (published). That should add up to 13.6k GVWR, but the published GVWR is only ~11k. So in reality his CCC is actually only around 4.4k. With fuel, hitch, pin weight, etc etc. he'll need to keep a close eye on his GVWR. But still good to go.

It can get confusing.. especially if you start considering things like... he's not actually towing 14k. He's towing 14k - pin which he is CCC'ing... and in reality... not even that since he's likely to not be maxing his 5er's cargo capacity. ;)

Any way you slice it.. the math seems to work. He's got some "OK" margins. Not "ideal" (in my book), but I don't think he'll be "white knuckling" it much. Not enough to warrant the expense of a TV upgrade (IMHO).

Link to comment
Share on other sites

I'll just add my opinion; instead of air bags, which can add roll when cornering with your 5er, I would add Timbren springs. They do not require monitoring air pressure or adjusting to suit conditions.

When towing make sure to air-up your truck tires to sidewall max, to reduce tire roll in corners or in cross-winds. This is one of the reasons a dually makes a better tow vehicle, it as 4 rear tires to counteract tire lateral forces imposed by the 5er in cornering. Of course there are kits sold to make a truck into a dually, but the negatives outweigh the benefits IMO.

One thing I'll add is, when calculating weights NEVER consider UVW=unloaded vehicle weight,unless that's the way you intend to travel.

An estimate of fully-loaded pin weight is obtained by dividing UVW into UVW pin weight to get pin weight  %. Next multiply GVW  X % to obtain fully-loaded pin weight. This assumes you loaded the 5er evenly.

 

2000 Winnebago Ultimate Freedom USQ40JD, ISC 8.3 Cummins 350, Spartan MM Chassis. USA IN 1SG retired;Good Sam Life member,FMCA ." And so, my fellow Americans: ask not what your country can do for you--ask what you can do for your country.  John F. Kennedy 20 Jan 1961

 

Link to comment
Share on other sites

So, I divided my UVW Pin Wgt by the UVW of the RV and got like 18%.  Taking it against the 13,649 GVWR = 2,515lb max pin wgt.  My truck has payload of 3,970 and my total GVWR of the truck is 11,500.  Looks like we'll be fine but I may go ahead and get bags.  

 

Thanks again!

Link to comment
Share on other sites

21 minutes ago, Darin Kent said:

Looks like we'll be fine but I may go ahead and get bags.  

Yup. Looks good.. and a solid plan, IMHO. Once you get your hitch in It wouldn't be a bad idea to take your 350 in to the scales with a full fuel tank and passenger (assuming you're not travelling alone) for some concrete numbers to work off of before purchasing your 5'er.

Looks like you're solid though.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...