I need help with weight ratings!

[KoloradoKamper]

Ok, I used to feel like I was a fairly intelligent man until we recently decided to purchase a 5th wheel. I have been trying to configure the size of 5th wheel we can safely tow and I am having a math meltdown. I would like to challenge some nobel prize winners to calculate an appropriate 5th wheel size.

TV is a Ford F-350 Super Duty 6.8L Super Duty diesel powerstroke V8. Single rear wheel. We purchased this vehicle so we can specifically get a larger 5th wheel. By my calculations the amount of trailer we can pull ranges from 9500 lbs to 15900 lbs.

The truck's GVWR = 11500 lbs and the GCWR = 21000 lbs (thus getting 9500 lbs). The ford web site put the towing capacity at 15900 lbs.

I thought the F-350 could tow about anything...I am finding I am way off on this. We destroyed an F-150 towing too large a trailer and I am not going to do it with this truck. I would like to pull something a little larger than a pop-up.

Any advice out there for a true tow math newbie. I feel like I have wasted a college and graduate school education... (just kidding)!

Thanks

[gitane59]

to the OP you have gotten alot of good technical numerical advice and lots of questions for you to think about.
From experience let me tell you my feelings from the seat of my pants.
We had a 2001 F350 SRW TV pulling a 26.5 ft light weight of about 9K lbs fifthwheel. Trailer was too light for the truck and did not have enough pin weight and produced a rough ride when towing (Overload springs bounced off their upper perches). If we towed with tanks full (tanks were ahead of the trailer's axles) the tow vehicle ride smoothed out.
We upgraded to the fifthwheel in picture below (about 15,500lbs ready to camp, depending on how loing of a trip) and while we kept the F350 SRW TV for several years towing the new trailer.
For the most part it towed the new trailer fine except when dealing with strong crosswinds and under very heavy braking. Also towing on broken pavement caused the SRW limitations to became apparent.
Just felt like the tail was wagg'in the dog a little to much for my confidence.

All weight's were under ratings but not by much. When time came to replace the F350 SRW we made the choice to get a DRW and towing has never been more confident.
If you stay under the published max of 15900 lbs and don't load the trailer and the truck to the gunnels for each and every trip you will be fine.

Now I know a couple who pulled a 21500lb GVWR Elite Suites fifthwheel with a F250 back and forth to Florida for several years (not what I would do or recommend), but they did live to tell about it and as far as I know were not ever stopped and weighed.

[NC_Hauler]

KoloradoKamper wrote:
I need to correct an error. My truck is a 6.4L power max diesel and the gcwr is 23000.

So, "supposedly", whatever you decide to tow, it and your truck combined, shouldn't weigh more than 23,000#....some ignore the numbers, so it's really up to you...again, you were given some pretty good advice when told to weigh your truck, loaded just like you're going camping, family, pets, full fuel tank, etc...add 200-250# for a 5er hitch, weigh...subtract that amount from your truck GVWR..what you have left tells you how much pin weight you can put in the bed of your truck..you can forget the GVWR numbers, a lot in here don't use them and go with how much weight your rear axle can take..gives you even more "pin weight" to play with...bottom line, your call...I would try not to go over the trucks GVWR or it's GCWR, but I'm one of the so called "weight police", so you can ignore most of what I've stated...:)

[ChooChooMan74]

Forum member ependydad has a good blog.

What can I tow?

[hmknightnc]

azdryheat wrote:
I'm pretty sure that Ford engineers and lawyers did some calculations with some built-in fudge factor when they came up with a 15,900# 5th wheel rating. You also can bet Ford knows what the pin weight would be on a 15,900# trailer and how much people and cargo would weigh. If Ford's lawyers thought for a minute that a buyer could get into trouble with the published numbers then they would have downgraded the 15,900.

The Ford engineers and lawyers would say you need to meet all the specs hence the OP's 9,500# calculation. This is the classic mistake made by individuals and not corrected by salesman. You have to be within wieght capacities and tow ratings to stay off the manufactures radar and it is the owner's responsibility to do this.

To the OP: You got good advice from others on how to calculate the wieght carrying capacity which will be your limiting factor on a single rear wheel truck not the manufactures tow rating when talking about a FW RV.

[KoloradoKamper]

I need to correct an error. My truck is a 6.4L power max diesel and the gcwr is 23000.

[2oldman]

KoloradoKamper wrote:
I thought the F-350 could tow about anything...I am finding I am way off on this.

Only a Class 8 semi tractor can tow about anything.

Almost anything can be towed..for a while. Then things start to break.

[azdryheat]

I'm pretty sure that Ford engineers and lawyers did some calculations with some built-in fudge factor when they came up with a 15,900# 5th wheel rating. You also can bet Ford knows what the pin weight would be on a 15,900# trailer and how much people and cargo would weigh. If Ford's lawyers thought for a minute that a buyer could get into trouble with the published numbers then they would have downgraded the 15,900.

[donn0128]

samandtheduck wrote:
I agree with Old-Biscuit up until the point where he said "GVWR of 15k". I was shopping for 5th wheels and was eliminating some of the trailers because the GVWR was higher than I wanted to pull. A salesman informed me that the GVWR doesn't always give you the information you want. The trailer I ended up buying has a GVWR of 16k. That is 2-7k axles and 2k on the pin. I have had it on the scales twice and one time it was 13.8k and the next time it was 14.1k. I hate to confuse you with more math but I would look at the dry weight and the carrying capacity. If it has a large carrying capacity and you only plan on carrying half that amount that is the number yoiu should be looking at. My problem is my pin weight is a little to much for the GVWR of my truck.
Brian

The big problem with your logic and IMHO the salesman did you a big disservice. But the problem is no one can predict how much YOU will pack into the trailer. At least using the GVWR number there is no surprises. BTW 2000 pin weight is awfully light for a fiver.
Heck my 13,500 pound (down the road) fiver normally carries 3000 pounds on the pin. Which is a bit over the magical 20% number most agree is optimal for towing a fifth wheel.

[samandtheduck]

I agree with Old-Biscuit up until the point where he said "GVWR of 15k". I was shopping for 5th wheels and was eliminating some of the trailers because the GVWR was higher than I wanted to pull. A salesman informed me that the GVWR doesn't always give you the information you want. The trailer I ended up buying has a GVWR of 16k. That is 2-7k axles and 2k on the pin. I have had it on the scales twice and one time it was 13.8k and the next time it was 14.1k. I hate to confuse you with more math but I would look at the dry weight and the carrying capacity. If it has a large carrying capacity and you only plan on carrying half that amount that is the number yoiu should be looking at. My problem is my pin weight is a little to much for the GVWR of my truck.
Brian

[NC_Hauler]

Old-Bisquit gave the OP some pretty good information...Weigh the truck loaded up just like you're going camping..add 200-250# for a 5er hitch and subtract that from your trucks GVWR of 11,500#...Example: If your truck, loaded weighs 8100#, subtract that from your GVWR and you have 3,000# you can play with for pin weight, (amount of weight you're going to put into the bed of your truck). Now, if the 5er you're wanting to tow has a GVW of 14,000#, take 20% of that, which "Ballparks" you a pin weight of 2800#, and there you go. 8100# weight of the truck plus 2800# pin weight =10,900#...your ready to go...Actually a lot of people don't give a flying flip about GVWR and go by the TV's rear axle weight rating..it'll allow you to carry more weight...tis' your call....What is GCWR of your truck..that is total weight you truck and 5er can weight together.

Just do yourself one big favor..don't use the 5er's "dry" or "empty" weight rating...use it's GVW, that is far more realistic and will help you in the long run.

good luck with your decision on which 5er to purchase.

[donn0128]

Old-Biscuit wrote:
Go weigh your truck.......camp ready (passengers, any stuff in truck etc.)
That's your actual truck weight.
Add 250# for 5th wheel hitch

Subtract that weight from trucks GVWR (11,500#).
That will be available payload (how much pin weight truck can handle before reaching GVWR)

Take 20% of GVWR of 5th wheel and use that as 'pin weight'

So if 5th wheel GVWR is 15,000.....pin weight would be roughly 3000# (rig loaded ready to camp)

Find the 5th wheel that meets your available payload.
With a GVWR of 11,500# on your truck you should have no problem with a 15K GVWR 5th wheel.

X2 almost. IMHO 15000 is too much for SRW truck. Keep your fiver search to a GVWR of around 12-13000 and you'll be happy

[therink]

Pick you year, make, model, engine, axle, etc. Everything you need to know here: Trailer Life towing guide

[Old-Biscuit]

Go weigh your truck.......camp ready (passengers, any stuff in truck etc.)
That's your actual truck weight.
Add 250# for 5th wheel hitch

Subtract that weight from trucks GVWR (11,500#).
That will be available payload (how much pin weight truck can handle before reaching GVWR)

Take 20% of GVWR of 5th wheel and use that as 'pin weight'

So if 5th wheel GVWR is 15,000.....pin weight would be roughly 3000# (rig loaded ready to camp)

Find the 5th wheel that meets your available payload.

With a GVWR of 11,500# on your truck you should have no problem with a 15K GVWR 5th wheel.