Drowning in knowledge regarding towing capability

[blue2004STi]

Hello Everyone,

I'm hoping that I can get some clarity regarding towing here.

Quick intro about myself, for the question you can skip down a little ways:

I grew up my whole life with pop-up campers and back in 2018 my wife and I bought an "old beater truck" (2007 silverado classic 4.8L V8 gas) for projects around the house, then in 2020 we bought a 2012 Coleman Niagara which we have enjoyed greatly.

I was never a "truck guy" but slowly found myself DD-ing the silverado every day. Then came the craving to upgrade the truck We talked it over and I theorized that we could upgrade the camper if the truck was bigger

After years of searching we finally found (what I thought was) "The Truck", a 2015 GMC 2500HD SLT Duramax 4x4 Crew Cab (All-Terrain edition). We had been looking at larger campers and settled on the idea of a lighter/shorter 5th wheel (thinking sub-13000 and sub-35'). I *thought* that the truck was capable of these numbers until we found a trailer we wanted to get serious about and started crunching actual numbers (not back-of-the-envelope). When I started going down the route of calculations I kept finding wildly different answers to the question "can I tow this trailer?". Been round and around and thought I'd see what you all had to say.

TLDR: HERE ARE THE SPECS/QUESTIONS:
Truck: 2015 GMC 2500HD SLT Duramax 4x4 Crew Cab (All-Terrain edition) with towing package
Truck Hitch: B&W drop in hitch system with companion slider (319lbs)
Truck Tires: Currently Kumho Road Venture AT51 LT305/55R20 20" with 3195lb/tire weight rating (going to move to smaller rim/tire combo with hopefully a higher weight rating)
Truck Curb Weight: could be 7384lbs (from GMC News Room, most likely), or 7749lbs (from a local dealer), or 7095lbs (from a different dealer) --> I've been using 7384lbs
Truck Max Load Weight/GVWR: 10000lbs (from door sill sticker)
Truck Max GCVWR: 24,500lbs (owners manual)
Truck Tow Capacity: 17,100lbs (Duramax owners manual)
Truck GAWR Front: 5200 (door sill sticker)
Truck GAWR Rear: 6200 (door sill sticker)
Truck Max Payload: 2793lbs (GMC News Room), 2289lbs (door sill sticker) <--- This one caused me a lot of confusion
Driver/Passenger Weight: 425lbs
Cargo Weight: 320lbs (Companion hitch)
Trailer Dry Weight: 11180lbs
Trailer GVWR Weight: 12495lbs
Trailer Pin Weight: 2115lbs

GMC Pressroom Link: https://media.gm.com/media/us/en/gmc...nali/2015.html

https://www.fifthwheelmagazine.com/new-tow-calc.aspx <-- This calculator says we barely violate payload, and violate GVWR by 250lbs
https://changingears.com/weight-calc...ht-calculator/ <-- This calculator says we can only tow a trailer weighing 6,762lbs...
https://rvingzone.com/towing-calculator/ <-- This calculator says we violate GVWR of the truck by 353lbs
Called Camping World in Colorado Springs and they said they would hitch me up with a 15000 trailer no problem
Used justanswer.com to link up with a gentleman who runs a mobile RV business who, after going around and around with the numbers on the GMC news room said "I should be more than fine"
Using the 2289 max payload number along with the 425 passenger weight + 320 Hitch weight and a 20-25% king pin weight percentage I get that we can't tow anything more than 6176-7720lbs...

Which way is up???????

Any help is greatly appreciated, thanks!

Matt

[TLStrickland]

You will be pushing it, but it should handle just fine. I watch olks towing triple axle toy haulers with the same 3/4 ton rigs all the time.

[notanlines]

Originally Posted by TLStrickland

You will be pushing it, but it should handle just fine. I watch folks towing triple axle toy haulers with the same 3/4 ton rigs all the time.

Of all the answers out there, let’s put this one on the back burner. I don’t believe “everyone is doing it” will solve the OP’s problem.
As previously mentioned, taking your truck over the scale will solve a multitude of problems.

[markcee]

Originally Posted by blue2004STi

Hello Everyone,

I'm hoping that I can get some clarity regarding towing here.

Quick intro about myself, for the question you can skip down a little ways:

I grew up my whole life with pop-up campers and back in 2018 my wife and I bought an "old beater truck" (2007 silverado classic 4.8L V8 gas) for projects around the house, then in 2020 we bought a 2012 Coleman Niagara which we have enjoyed greatly.

I was never a "truck guy" but slowly found myself DD-ing the silverado every day. Then came the craving to upgrade the truck We talked it over and I theorized that we could upgrade the camper if the truck was bigger

After years of searching we finally found (what I thought was) "The Truck", a 2015 GMC 2500HD SLT Duramax 4x4 Crew Cab (All-Terrain edition). We had been looking at larger campers and settled on the idea of a lighter/shorter 5th wheel (thinking sub-13000 and sub-35'). I *thought* that the truck was capable of these numbers until we found a trailer we wanted to get serious about and started crunching actual numbers (not back-of-the-envelope). When I started going down the route of calculations I kept finding wildly different answers to the question "can I tow this trailer?". Been round and around and thought I'd see what you all had to say.

TLDR: HERE ARE THE SPECS/QUESTIONS:
Truck: 2015 GMC 2500HD SLT Duramax 4x4 Crew Cab (All-Terrain edition) with towing package
Truck Hitch: B&W drop in hitch system with companion slider (319lbs)
Truck Tires: Currently Kumho Road Venture AT51 LT305/55R20 20" with 3195lb/tire weight rating (going to move to smaller rim/tire combo with hopefully a higher weight rating)
Truck Curb Weight: could be 7384lbs (from GMC News Room, most likely), or 7749lbs (from a local dealer), or 7095lbs (from a different dealer) --> I've been using 7384lbs
Truck Max Load Weight/GVWR: 10000lbs (from door sill sticker)
Truck Max GCVWR: 24,500lbs (owners manual)
Truck Tow Capacity: 17,100lbs (Duramax owners manual)
Truck GAWR Front: 5200 (door sill sticker)
Truck GAWR Rear: 6200 (door sill sticker)
Truck Max Payload: 2793lbs (GMC News Room), 2289lbs (door sill sticker) <--- This one caused me a lot of confusion
Driver/Passenger Weight: 425lbs
Cargo Weight: 320lbs (Companion hitch)
Trailer Dry Weight: 11180lbs
Trailer GVWR Weight: 12495lbs
Trailer Pin Weight: 2115lbs

GMC Pressroom Link: https://media.gm.com/media/us/en/gmc...nali/2015.html

https://www.fifthwheelmagazine.com/new-tow-calc.aspx <-- This calculator says we barely violate payload, and violate GVWR by 250lbs
https://changingears.com/weight-calc...ht-calculator/ <-- This calculator says we can only tow a trailer weighing 6,762lbs...
https://rvingzone.com/towing-calculator/ <-- This calculator says we violate GVWR of the truck by 353lbs
Called Camping World in Colorado Springs and they said they would hitch me up with a 15000 trailer no problem
Used justanswer.com to link up with a gentleman who runs a mobile RV business who, after going around and around with the numbers on the GMC news room said "I should be more than fine"
Using the 2289 max payload number along with the 425 passenger weight + 320 Hitch weight and a 20-25% king pin weight percentage I get that we can't tow anything more than 6176-7720lbs...

Which way is up???????

Any help is greatly appreciated, thanks!

Matt

You are on the right track with your calculations. Available payload is vehicle GVWR minus curb weight. Only way to know for certain where you stand is to weigh the truck. That's what they did at the factory to come up with that 2,289 payload capacity. The truck was weighed after assembly and evidently weighed 7,711 lbs (10K - 2,289). A weight allowance is made for a full tank of fuel, as well.

The lack of payload cap is the primary drawback of a 3/4 ton diesel.....great engine, but it weighs about 800 more lbs than a gas engine, and heavier truck = less payload. That is why you often see the suggestion on forums to 'skip the 3/4 and move directly to a 1 ton'.....its still a heavy truck, but the GVWR is increased, giving more payload. The diesel equipped 3/4 ton may be capable of pulling 15K lbs, but it can't carry it without being overloaded.

Even going with a low end 20% pin weight and a 10K GVWR trailer, you ate up the bulk of your 3/4 ton's payload before you even get behind the wheel.

As for what the dealer's are telling you....they either are ignorant on the numbers or they don't care. They are in it to sell you a trailer. The fine print in the trailer owner's manual states it's incumbent upon the buyer to ensure they have a 'properly equipped tow vehicle.'

The bright side is that at least you haven't bought the trailer already. Many here (myself included) have been in that situation.

[JRTJH]

Right now, you have ONE number that's valid. The truck GVWR. The payload WAS accurate when the truck left the factory, but when you or a previous owner installed floormats, added air bags, stuck a took kit under the back seat, hung running boards on the sides, put maps or a road atlas or a GPS in the front seat, you changed that payload by whatever weight has been added. Looking at your "tires and wheels" they don't weigh what came from the factory, so they will also alter your payload....

As posted above, the ONLY way to know what your payload is NOW, is to put the truck on a scale and weigh it, then subtract the weight from 10,000 pounds. That's your "current payload".....

All the other numbers you've listed are "brochure/marketing division data" and are NOT reflected in the reality of any truck that was built. As an example, you can't have the "brochure towing capacity without the optional towing package, but the towing package reduces the payload if it's added to the "brochure payload".... So, damned if you do and damned if you don't.....

I'd recommend that the first step in determining the "valid payload remaining for YOUR truck" is to put it on the scale.... Then you're not "guessing" but are dealing with "real numbers"...

As for towing a 13K fifth wheel with a 3/4 ton diesel truck, being the owner of a 2015 Ford F250 diesel, I can assure you that "it ain't happening".... Not if you intend to stay within ALL the ratings for the truck. And, GM, Ford and RAM all three state in the owner's manuals that ALL ratings must be observed when determining the capability of their vehicle.....

Add an "almost 350 pound sliding hitch" and you just made the hard to achieve weights even more impossible to achieve.....

Weigh your truck and deal with "accurate real numbers" not "brochure marketing data that's specifically written to sell trucks"...

All that said, as posted above, your truck will PULL a 13K trailer all day and likely never break a sweat.... However, it won't do it and stay within all the ratings..... The first you'll likely "break" is the payload. You're looking at a pin weight closer to 2800-3000 pounds, then add the hitch and you're going to be well over 3000 pounds, even in the most conservative estimates... Add passengers and cargo and you're nearing the 4000 pound range....

No diesel 3/4 ton truck I've ever seen has anywhere close to that kind of payload....

[wiredgeorge]

Too many numbers make the head spin. To get a rough idea, a fifth wheel is about 23 percent of the gross weight of the trailer. A 12495 lb gross weight trailer will have a 2874 lb pin weight and add you 800 lbs for hitch/passengers and you are at 3675 lbs. payload. Your specific truck's payload is the TOTAL AMOUNT THE TRUCK IS RATED TO CARRY...2289 lbs.

The tow capacity in a brochure and the published pin weight by the camper manufacturer are not real world numbers. You don't have enough truck. Even a 10K gross weight 5th wheel is too much. You will still be over payload with a 7000 lb gross weight 5th wheel. New truck or bumper pull are the only safe answers. A bumper pull camper is about 13 percent of the trailers gross weight on the pin; again add hitch/passenger weights. You would be golden with a 35' bumper pull (they are about 10K gross weight from the Keystone website).

[dutchmensport]

Originally Posted by wiredgeorge

Too many numbers make the head spin. ....

I think that was the only statement I understood on this entire thread!

I tow with a 3500 diesel dually long bed crew cab. No issues towing anything. Go big and you'll never --- EVER have to figure it out "ever" again. It's when you go to a triple axle trailer you'll need to struggle with the math again.

[travelin texans]

First bit of advice is DO NOT use any numbers from brochures, they're all based VERY conservatively on the rv dry weight which will never exist once that rv arrived at the dealer.
And absolutely NOTHING the rv salespersons spews out of their moving lips, most don't know or care a thing about whether you can safely tow anything, they want to sell you a rv......you.
You've already been given very sound advice on this forum, so all that other stuff just file away in File 13.

[rhagfo]

Well based on your numbers you are about 700# overweight, with the trailers dry pin weight. At GVWR the pin could be about 2,700#, now about 1,300# over GVWR. The 2,289# payload is what YOUR truck as it left the assembly line, being a 2015 best to weigh it to establish current available payload.

[jasin1]

The payload capacity of that fifth wheel seems really low to me (unless m missing something)….could be pretty easy to go over that number also and put added stress to already marginal trailer axles and tires…and increase your pin weight

[rhagfo]

Originally Posted by jasin1

The payload capacity of that fifth wheel seems really low to me (unless m missing something)….could be pretty easy to go over that number also and put added stress to already marginal trailer axles and tires…and increase your pin weight

Jasin, I agree his numbers seem to point to a low 5th wheel payload.

Trailer Dry Weight: 11180lbs
Trailer GVWR Weight: 12495lbs
Trailer Pin Weight: 2115lbs

12,495# - 11,180# = 1,315# 5th wheel payload, that is ridiculous for a 5th wheel in the 30' to 35' is very low.

It would help if the OP would list the make and model of the 5th wheel they are looking at, but the numbers given just don't work.

[travelin texans]

Originally Posted by rhagfo

Jasin, I agree his numbers seem to point to a low 5th wheel payload.

Trailer Dry Weight: 11180lbs
Trailer GVWR Weight: 12495lbs
Trailer Pin Weight: 2115lbs

12,495# - 11,180# = 1,315# 5th wheel payload, that is ridiculous for a 5th wheel in the 30' to 35' is very low.

It would help if the OP would list the make and model of the 5th wheel they are looking at, but the numbers given just don't work.

Not to mention that published pin weight is less than 20% of the dry weight, not even close in the real world pin weight, way too many inaccurate or incorrect numbers to even begin to calculate.
No wonder the poor guy is "drowning in weight information", so far has no useful numbers other ther the posted payload from his truck & that's not the scaled number.
The worst advice yet is that someone sees others doing it so should be fine. That's the kind of advice that gets others in those unsafe situations.
Fortunately the OP is doing his due diligence to find out before he gets in over his head. Congratulations for doing so!

[Canonman]

Unless you're willing to upgrade the truck, the other option is to look at a smaller 5th wheel. The stickered payload on our 2007 Ram is 2160#. Our 30' Cougar loaded for a week of dry camping in Teton NP has a confirmed pin weight of 1920#. These actual weights are different from the "posted" weights from the manufacturers due to options that were installed and the real world loading when you're getting ready to camping.
Bottom line, you're going to overload your GMC with the trailer you're considering. Good news is you have the luxury of changing to smaller/lighter trailer before it's too late.
Of course, all red-blooded males would want the new, bigger, faster, stronger truck

[blue2004STi]

Thank you to everyone for the responses. After the realization that time was not a factor since this truck just "cannae do it" work got ahold of me so I wasn't able to respond until now... I think I'm starting to wrap my head around the various numbers and their importance.

So I followed the advice from markcee/JRJTH/rhagfo and went and weighed the truck using a CAT scale. I was standing on the front pad, full tank, etc... and came up with:

Steer Axle - 4840lb
Drive Axle - 3260lb
Gross Weight - 8100lb

I weigh ~215 pounds so I assume I can take that off of the front axle (not that it's important since I wasn't by the rear axle).

I take it that this means I have the following:
Curb weight - 8100-215 = 7885 lbs

With owners manual numbers of :
GCVWR = 24,500lbs
Towing Capacity = 17,100lbs --> 14,000lbs (camping guy says with my configuration and gear ratio of 3.73 this is down graded to 14,000 which is more conservative so I shall use this)

Then there is numbers from the vehicle itself
GVWR = 10,000lbs
GAWRfront = 5200lbs
GAWRrear = 6200lbs

These to me are the pertinent numbers. All of this indicates to me the following:
Rear Axle Weight Capacity - 6200-3260 = 2940lbs
Payload Capacity - 10000-7885 = 2115lbs

Meaning that my payload capacity is my true limiting factor for towing with this particular truck. If this is all true, I'm not sure there are 5th wheels we would fit the bill for us that will work weight wise.

Canonman, you are exactly right. My testosterone tells me I want a bigger truck to make this happen but the truck market around me and my bank account say otherwise

I think I'm understanding correctly that 5ers normally have a 15-25% pin weight range (possibly higher) and that travel trailers normally sit in the 10-15% range (with a weight distributing hitch), correct?

Given the payload being the limiting factor and assuming 425lb passenger weight I get the following max GVWR for the possible trailers:

5th wheel (assumes 320lb hitch):
15%(unrealistic) pin weight = (2115-425-320)/0.15 = 9,133lbs
25% pin weight = (2115-425-320)/0.25 = 5,480lbs

Travel trailer (assumes 100lb weight distributing hitch): <-- This is new but same concept
10%(unrealistic???) pin weight = (2115-425-100)/0.1 = 15,900lbs (this would be limited by the 14,000 towing capacity correct?)
15% pin weight = (2115-425-100)/0.15 = 10,600lbs

If that's true then I think the travel trailer with a dry weight of around 8500lbs seems reasonable...maybe...???

For anyone that was asking about the weights of the original 5er that we looked at, it was a 2015 Keystone Cougar 338PAT and I got the weight specs I was using here: https://www.rvusa.com/rv-guide/2015-...338pat-tr21145

Thank you all for your patience and for reading through my (hopefully not) non-sensical calculations.

Matt

[wiredgeorge]

Your truck's ACTUAL payload is 2289 lbs. A typical bumper pull camper hitch weight is 13 percent of it's gross weight. This would be 1105 lbs. A little more or less won't make a great deal off difference. Add hitch and passenger weights and stuff in the truck and you should be golden with an 8500 lb bumper pull. You should be fine with up to an 11K gross weight bumper pull. The longer the camper the more the need for a good quality hitch so it doesn't sway and the load is distributed properly.

[army1rob]

If you go off what some of the members on this forum say then probably 99% of people pulling 5th wheels with a 3/4 ton pick up would be overloaded. I see more people pulling 13-15k 5th wheels with a 3/4 ton than a 1t. I am not saying they are right but are they wrong? I pull a 20k toy hauler with a 1t SRW because I can’t park a dually in my garage. I am in Utah and refuse to park outside since it is my daily driver. My average tow with my trailer is under 500 and I probably tow 6-10 times a year. Most of those trips are with my best friend and his family and he has the same truck in a 3/4 ton towing a 14k 5th wheel. We obviously pull mountains and steep terrain and do just fine. The dealer doesn’t care about payload and the majority of people out there don’t either. Kudos to you for coming on here and looking for the right answer but I would tell you that is really about what you are comfortable with. A 5th wheel tows smoother and there is less sway than a TT. I towed my toy hauler with a 3/4 a couple of times and really only bought a 1t because I wanted a long bed. I can honestly say that the 1t rides like crap as a daily driver and I miss my 3/4. You do you and as long as you are comfortable you will be fine.

[notanlines]

[rhagfo]

Originally Posted by army1rob

If you go off what some of the members on this forum say then probably 99% of people pulling 5th wheels with a 3/4 ton pick up would be overloaded. I see more people pulling 13-15k 5th wheels with a 3/4 ton than a 1t. I am not saying they are right but are they wrong? I pull a 20k toy hauler with a 1t SRW because I can’t park a dually in my garage. I am in Utah and refuse to park outside since it is my daily driver. My average tow with my trailer is under 500 and I probably tow 6-10 times a year. Most of those trips are with my best friend and his family and he has the same truck in a 3/4 ton towing a 14k 5th wheel. We obviously pull mountains and steep terrain and do just fine. The dealer doesn’t care about payload and the majority of people out there don’t either. Kudos to you for coming on here and looking for the right answer but I would tell you that is really about what you are comfortable with. A 5th wheel tows smoother and there is less sway than a TT. I towed my toy hauler with a 3/4 a couple of times and really only bought a 1t because I wanted a long bed. I can honestly say that the 1t rides like crap as a daily driver and I miss my 3/4. You do you and as long as you are comfortable you will be fine.

Originally Posted by notanlines

army1rob, have you ever put your rig on a scale loaded? When you do look at the weight you have on your tires and rear axle. You are likely exceeding both weights.
The issue isn't can it PULL it, it is can you carry it, does your one ton have air bags to fix rear sag? They don't increase tire capacity.
You are playing Russian Roulette with your safety and others on the road.

[wiredgeorge]

Originally Posted by rhagfo

army1rob, have you ever put your rig on a scale loaded? When you do look at the weight you have on your tires and rear axle. You are likely exceeding both weights.
The issue isn't can it PULL it, it is can you carry it, does your one ton have air bags to fix rear sag? They don't increase tire capacity.
You are playing Russian Roulette with your safety and others on the road.

I think legal liability might come into play if there is a wreck. Will an insurance or LEO investigator notice being overloaded (exceeding payload) and say, "heck, everybody is doing it...."?

[flybouy]

Originally Posted by wiredgeorge

I think legal liability might come into play if there is a wreck. Will an insurance or LEO investigator notice being overloaded (exceeding payload) and say, "heck, everybody is doing it...."?

I was in traffic court (as a witness) a few years ago and this reminded me of a case before the one I was there for. A young man was charged with speeding, driving 75 in a 65 mph zone. He said it wasn't fair because other cars were passing him when the cop "picked him" to ticket. The judge asked if he was speeding and he said he was. The judge said guilty! The judge said because others were breaking the law it did not justify you doing it.