Advice on Towing

[Jr66]

I have GMC 2007 LWB SRW 3500 Duramax 6.6L
GVWR 9900lbs
FRT GAWR 4800 lbs
Rear GAWR 6500 lbs

Vehicle Empty
Net 7766lbs
Front 4444 lbs
Rear 3322 lbs

I want to purchase a Cougar 330 RBK
Dry 10035 lbs
Hitch 1865 lbs
Cargo 2230 lbs

This was my first trailer Cruiser 30QB. This trailer pulled like it wasn't there.
Dry Weight: 8035
GVWR: 12000
Carrying Capacity: 3436
Hitch Weight: 1840
Axle Weight: 6195
Exterior Length 34' 3"
Exterior Height: 12' 4"

and this was my second trailer Sierra Select 32QBBS
Not much different than 1st trailer but did not tow as easy as I thought. ALso had a very flat front cap.
Dry Weight 8850lbs
GVWR 13896lbs
Cargo Capacity N/A
Hitch Weight 1896lbs
Axle Weight N/A
Exterior Height 13.00'
Exterior Length 36.92'

Now thinking of Cougar 330 RBK
Shipping Weight 10035
Carrying Capacity 2230
Hitch 1865
Length 37' 4"
Height 12' 10"

2 questions.
Will I exceed my max hitch weight rating of my truck? I think it is rated for 2500lbs

Also do you think this will pull ok, hitch weight the same, dry weight is heavier?

Thanks

[Roam America]

You did not include the weight of your truck. That is a crucial number. Load it up like you would when ready to tow (passengers, fuel, gear) and get it weighed. Only then can you do the math. I am guessing it will weigh around 8000#. But that is a SWAG at best. That said you should have around 1900# available for pin weight.

Always use the GVWR for the trailer unless you do not intend to put anything in it. Using GVWR will give you a buffer. To calculate the pin weight, figure roughly 18% of the GVWR, So for your Cougar the actual pin weight is around 2160# which would put you a little over the trucks GVWR. For your second 5er, the pin weight would be roughly 2501#; again a bit over. But you really need to weigh your truck to know for sure.

If you want to use something less than GVWR of the trailer in the calculations, be careful and good luck.

Please understand that it is about more than pulling the trailer. You need to stop it too, sometimes in a panic situation. And you should also consider the wear and tear on the truck and suspension. Running over weight could shorten the trucks life. Not to mention how the insurance company will support you should you ever be in an accident (knock on wood you never have to worry about this point).

[Jr66]

My truck with both axles on the scale is 7044lbs. Using axles axle 1 + axle 2 + people is equal 8166lbs.

The max hitch according to manufactures book, see attached

I am totally confused why my hitch would be over?

I do wany to be safe for brafking etc, that is why I am making sure.

Thanks

[Roam America]

Here is the best advice I can give you.


The max trailer wieght numbers that the manufacturers quote are for a truck with a 150# driver and no options. It does not account for gear and additional occupants. You will see below that, after running the numbers, your actual max trailer weight is more like 11,800 as opposed to 14,700 that the manufacturer numbers state.


Using GVWR/GCWR #'s and actual weight for your truck (9,900#, 22,000# and 8200# (rounded up) respectively) and the Cougar 330 RBK GVWR (12,000) and using the 20% of GVWR rule for pin weight for estimated pin weight (20% = 2400). GVWR (9900) minus truck weight (8200) leaves you with 1700# for pin weight. Using truck weight + estimated pin weight (8200 + 2400 = 10,600) which says you are 700# over your trucks GVWR of 9900#. Using the weight of your truck plus the trailer GVWR (8200 + 12000) you are at 20,200# or 200# over your trucks GCWR. All of this is strictly using the math and maximum numbers. An example; my trailer pin weight is actually 17% of the trailer GVWR, which is why the 18-20% number is for estimiation purposes but fairly accurate. You wouldn't know that until you load up the 5er and weight it. It depends on how the weight is distributed. Additionaly, if you never pack your trailer to GVWR, you can stay under the trucks GCWR and reduce the pin weight. In other words you are pretty much at the max ratings for your truck. The other trailer would put you over even more.

Hope this makes sense. Maybe someone else will be along to explain it better.

[Roam America]

now there will be others who will lable me the "weight police" and that all will be good. If you stay under the GVWR of the 5er and monitor weight distribution you very well may be OK. I am just telling you what the math is telling me using your trucks actual weight.

[SmokeyWren]

Originally Posted by Jr66

I have GMC 2007 LWB SRW 3500 Duramax 6.6L
GVWR 9900lbs
Vehicle Empty Net 7766lbs
...
I want to purchase a Cougar 330 RBK
Dry 10035 lbs
Hitch 1865 lbs
Cargo 2230 lbs

Dry weight is almost meaningless other that to compute approximate percentage of hitch weight = 18.58%. Use the trailer's GVWR to determine probable wet and loaded trailer weight. Use 18.58% of trailer GVWR to determine wet and loaded hitch weight.

Trailer GVWR (shipping weight plus cargo capacity) is 12,265. 18.58% hitch weight is 2,279.

Truck GVWR of 9,900 with truck weight of 7,765 leaves only 2,135 pounds available for passenger(s), tools, 5er hitch, and any other payload. You're going to be overloaded with just the hitch weight, before you add any passengers or other cargo.

Will I exceed my max hitch weight rating of my truck? I think it is rated for 2500lbs...

With a GVWR of 9,900 and empty truck weight of 7765, your actual available payload is only 2,135. So with a hitch weight of 2,279, you're going to exceed the GVWR of your truck before you load the truck with passengers and any tools or other cargo.

Also do you think this will pull ok, hitch weight the same, dry weight is heavier?

Again, dry weight is useless info. Nobody tows a try trailer. And no, it will not be okay. Your Duramax is more than enough powertrain to pull a 12,265 pound trailer, but you don't have enough truck to haul the wet and loaded hitch weight of 2,279 pounds.

(That's why they make one-ton duallys.)

[JIMNLIN]

don't know where you came up with those numbers but they aren't from a scale. Scale weights are in 20 lb or 50 lb increments. Lets use them anyway to see where the numbers go.

The trailers pin weight sits over the trucks rear axle. Your one ton SRW has a 6500 RAWR for carrying the pin weight from the trailer. Front axle carries little to no weight. Your trucks rear axle has a 3322 unladin weight which leaves the truck with a 3178 lb payload. Does that include a hitch ??

Now lets look at the trailer. Using your numbers it has a 10035 lb shipping weight and a 2230 lb CCC = a 12265 lb GVWR. using 20 percent may have 2450 lb max pin weight. With a 3178 lb payload your one ton SRW will handle that size 5er fine.

Or you can use the trucks GVWR to figure axle loads. Both are safe.

[RustyJC]

The truck's GVWR is there for a reason. It's one of the ratings that the manufacturer states is not to be exceeded, along with the GCWR and the GAWRs. I wouldn't recommend ignoring any of them.

Rusty

[myredracer]

Hi, new to this forum so please forgive me if I have misunderstood something in this thread. You cannot exceed anyone of GVWR, front GAWR or rear GAWR. That's what the government and vehicle manufacturer will tell you. So if you are going to load up the rear axle to it's max. available capacity in this case, you can't. Assuming that no weight is added to the front axle measured weight of 4,444 lbs, you can only add a max. pin weight of 9,900 less 4,444 less 3322 = 2234 lbs.

So, this means that the max. you can carry on the rear axles without exceeding the GVWR is 2234 + 3322 = 5,556 lbs. The result is that this is under the rear GAWR of 6,500 lbs. You have about 1,000 lbs of safety margin on the rear axle but only about 350 lbs on the front, so I would be careful that you don't end up transferring some load to the front. However, if your scaled weight of 7766 lbs is only for driver and fuel, then you may end up being in a position where you can't carry passengers or anything else in the truck with your proposed camper.

You would take the 2,234 lb number and work back to see what the max. trailer you can handle is, and adjust it accordingly for weight of passengers and some possible gear in the truck.. Am I wrong on this? I just noticed a post by Rusty which would back some of this up.

It would seem to me that you need to reconsider and look at a lighter and/or shorter camper.

[elkhornsun]

Easy enough to increase the rear payload of the truck to accommodate the pin weight. The GCWR is the upper limit that you cannot change. Not sure about your model but the current 2500HD Duramax long bed trucks have a conventional tow limit of 13,000 lbs. and a 5th-wheel tow limit of 17,400 lbs. You are pushing it with your planned loaded trailer tow weight. I would look for a trailer with a dry weight no greater than 10,000 lbs. and less is more in terms of having more reserve capacity for water and waste and adding batteries for boondocking etc.

[RustyJC]

Originally Posted by elkhornsun

Easy enough to increase the rear payload of the truck to accommodate the pin weight.

The GVWR and rear GAWR shown on the driver's door sticker are limits certified by the manufacturer for that particular truck. Although one can change springs, tires, add airbags, etc., the manufacturer's GVWR and rear GAWR do not change from the values shown on the door sticker.

Rusty

[Jr66]

Just wanted to follow, I ended buying the Cougar 320QBS instead of the 330 RBK but th esticker numbers are very close. See below.


Shipping Weight 9630
Carrying Capacity 2570
Hitch 1960
Length 36'11"
Height 12'5"
Fresh Water 60


Here is trailer and truck with me in it

Font 4440 lbs
Rear 5565lbs
trailer 8120 lbs



But the actuals when trailer had 2 adults, 3 kids, full tank of diesel, fresh water tank full 60 gallons, trailer stocked with gear, food tools, bbq so on are

Font 4640 lbs
Rear 5670 lbs
trailer 8730 lbs

[SmokeyWren]

Originally Posted by Jr66

But the actuals when trailer had 2 adults, 3 kids, full tank of diesel, fresh water tank full 60 gallons, trailer stocked with gear, food tools, bbq so on are

Font 4640 lbs
Rear 5670 lbs

GVW = 10,310 vs. GVWR of 9,900. 410 pounds overloaded. Not bad. Probably all you need is air bags inflated only enough to not blind oncoming drivers at night, plus keep rear tires inflated to 80 PSI when towing.

But not good either. When you trade tow vehicles, be sure the replacement has GVWR of 10,500 or more, which includes any 2005-up F-350 SRW diesel. I don't keep up with GM and FIAT, but I'll bet their late-model 3500 SRWs also have more than 10,500 GVWR.

On edit: Just for grins, I checked the factory specs of the new GMC 3500 SRW 4x2 with the long bed. GVWR with gas engine is 10,700. GVWR with diesel engine is 11,400. Almost as much as a Ford.

[Franka548]

If you only put 20 gal of water in the fresh water tank, you will take off approximately 300#, depending on where the fresh water tank is located, will tell you if it comes off the truck or the trailer weights. Also, if you can move some of the heavier things from your front storage compartment and move it behind the trailer axles will help also. You are probably going to still be slightly over your GVWR , but if you watch how you load the truck and trailer, you should be able to get it down to around 100# over.
Frank