need advice on tow weight

[TBrase]

I've learned a lot reading all of your posts and have come down to two potential 5th wheel RV for purchase: Grand Design M-Class 328 or Open Range Mesa Ridge 346FLR.

 

One thing I have learned is that my pickup will not pull any 5th wheeler and even if it will pull it, stopping it is just as important. So the numbers are:

 

Pickup = 2014 2500HD Chevy CrewCab 4wd with standard bed and 6.6 diesel; tow capacity 15,800 lbs

 

OR 346 = Dry weight /UVW 10245lbs with approximately 1500 lbs of gear/personal stuff/food/supplies for a total est weight of 11745 (I don't believe there should be any problem pulling or stopping this)

 

GD 328 = Dry weight /UVW 12400 lb with approximately 1600 lbs of gear and etc (larger water tanks) for a total est weight of 14000 (this I am not so sure of?)

 

I feel confident the 6.6 diesel will pull the Grand Design, but I need some opinions on the safety and stopping. (plan on doing the rockies)

 

What do you all think? Am I close on the estimated weight of gear and stuff?

[TreyandSusan]

Plan by using the GVWR of the trailer.

Be concerned with the capacity of the Rear GAWR of the Truck.

The basics can be found in this towing video.

Terms and definitions can be found in this weight glossary.

[Jimalberta]

Also figure out the pin weight of the trailer at GVWR. Its very easy to overload the truck rear axle and tires. Give yourself some extra capacity on the load capacity of the truck for other loads. I ended up adding an extra fuel tank in the box of my truck. 50 gallons of diesel came to 350 lbs. plus I had a tool box with probably 200 lbs worth of tools, oil, extra antifreeze...etc, etc. my truck was a 1 ton dually so no issue with its capacity but a 3/4 ton single rear axle is not in that league.

[lenp]

I cannot speak for others but when we purchased our last fiver (back in 2007) we did a before and after weight comparison and found that we loaded nearly 3000 pounds of STUFF into it. That did not include water and propane. We had been full time for 8 years at the time and accumulated a fair amount of stuff.

 

Might want to reconsider your 1500 pounds.

 

Lenp

[skp51443]

If you load it to 100% of the rated weight you may be unhappy, read the fine print on the towing guide about how the truck was set up and what size trailer they pulled.

[TreyandSusan]

My Physics professor used to qualify his examples and calculations by starting off with "in a frictionless environment". I understand why he did this, but I don't really live in outer space.

To add to what Stanley was saying, the Marketing Departments of the auto manufacturers generate the towing guides and they are driven by sales. The vehicles they used are not quite the same as what you will be towing. This is not bad or evil it is just something we need to remember and consider. The towing guide is a place to start but you need to plan in a great deal of extra room on all the primary safety ratings. GAWR GVWR GCWR. The auto manufacturers increasingly leave out details that are helpful to those who plan to tow much more than the occasional weekend or two week annual trip.

 

Almost everyone (including me and my wife) underestimates weight, even when using a scale to measure stuff before finding a new spot inside the trailer or truck. Everyone is different - we travel differently, have different values, interests, and habits. Some will travel short distances to a from family, some will travel in the mountains. While it does help to get an idea about what others do, each person must learn and understand the basics to make a decision for what they want to do.

 

There is no good way to guess what the pin weight will be once the trailer is loaded. Weighing the vehicle on scales is always the best thing to do. If you carry a generator in the front compartment with a bunch of tools then it will be heavy. Dry pin weigh means virtually nothing for a fifth wheel, because most of the storage is in front of the axles and each person carries different stuff. A place to start is 20-25% of the GVWR of the trailer.

 

55-60% of fifth wheels and tow vehicles are exceeding at least one safety rating.

[bigjim]

I was in a Ford dealer yesterday and as long as I was there thought I would pick up the truck brochure. Just read part of it earlier. talks about the 150lb driver and nothing I could find about frontal area of towed vehicles. Seems there might be and additional information guide or you have to talk to a dealer for additional info. Nothing about how much fuel but a generic statement about added stuff like a 5thW hitch. I have a sneaking suspicion that almost all folks towing with a 250 - 350 and any larger 5thWheels are overloaded.

[reed and elaine]

Agree fully with TreyandSusan. Should weigh the rig on CAT or similar scales and keep well within the limits of wheels, frame, and pin weight. We weigh the fully loaded pickup (full regular and auxiliary 50 gallon tank, 4 x 6 gallon Jerricans of water, 2 x propane canisters), and then weigh the complete rig with full 81 gallons of fresh water). We are about 1000# under on 5th wheel axles (Open Range 337RLS - and you can put almost 4000# load into this 5th wheel to include the water and propane etc) and about 800# ligh on the dualie rear end/pin weight.

 

It is important to realize that you might be boondocking and have 30 or more gallons in each of the grey and black tanks and quite a bit of water in the fresh water (the Jerricans are carried so that we can drive off to a water point to maintain our freshwater tank). It might be possible to be carrying 150 gallons of water (1200#).

 

Conventional wisdom seems to be to go over your Stuff every six months or so and either throw out/store that which you have not used. Tools/car jacks/etc are not part of this equation. Pack for your planned area: take snorkeling stuff to Yucatan and not to Alaska etc.

 

Agree with Bigjim that a lot of folks are towing above their limits. Totaled previous rig in 70-vehicle whiteout near Puebla, Mexico (10 vehicles piled into our rear end in succession - very interesting situation - was not much of a bump by the time the 10th vehicle or so hit the conga line) We have become far more circumspect since then regarding roadweather conditions and care in being well within limits of tires/brakes etc.

 

Not boondocking for the next three months since we're flying down to Ecuador and Peru for three months. Galapagos and Machu Picchuare top 2 on bucket list.

Reed and Elaine

[LindaH]

Your starting point should not be the dry weight of the fifth wheel because dry weight is pretty much a meaningless number since it usually doesn't include any manufacturer-added options and certainly doesn't include any dealer-added options (and if it's a used unit, it will not include owner-added options). As TreyandSusan said, use the GVWR of the fifth wheel instead and figure 20%-25% of this amount as the pin weight.

 

Also, that 15,800# towing capacity on your truck is for a basic truck with no options (other than those needed to get to that towing number), about an eighth of a tank of fuel, no gear, and only one 150# driver. So, once you load up your truck with all passengers, pets, and gear that will normally be in the cab or bed of the truck (including a fifth wheel hitch), the 15,800# will be something lower (and this totally ignores the fact that the published tow rating is calculated assuming around a 60 sq.ft. frontal area...think horse trailer...rather than the much larger frontal area of most fifth wheels).

 

Since you already have the truck, you can determine the maximums your truck can handle without exceeding any of its ratings:

 

Load the truck up like it will be for any trip with all the people, pets, and gear that will normally be carried by the truck, either in the cab or in the bed, and a full tank of fuel. Now take the truck down to the local scales and get it weighed (total, front axle, and rear axle). If you don't already have a fifth wheel hitch, add about 200# to the scale weight.

 

Now that you know the *real life* weight of your truck, subtract this weight from the truck's GCWR...that will give you the MAXIMUM loaded weight of any fifth wheel you should be towing (and, as Stanley mentioned, you don't really want to tow at maximum). Then subtract the truck's weight from its GVWR...that will give you the MAXIMUM pin weight your truck can handle (as stated above, use 20%-25% of the fifth wheel's GVWR for an estimated pin weight). Add this estimated pin weight to the rear axle weight when you weighed your truck...since nearly 100% of the pin weight rests on the rear axle, this will tell you whether or not the rear axle will be overloaded.

[Jimalberta]

I would add another 1500 lbs to the total weight of each trailer. This puts the second option at the top end of a 3/4 ton's capacity.

 

On the positive side that 2014 truck with the Duramax Allison combo is a wonderful towing rig. It has great engine braking characteristics for doing mountain descents and plenty of power for going up the grades. You have a great truck...... now to just avoid over loading it.

[TXiceman]

AS noted, forget the dry weight and work from the GVWR of the trailer. Also, carefully rear the foot notes on the truck towing rating and you will find you need to reduce the towing capacity by a large amount.

 

And the final note is NEVER believe the RV sales person. Few of them have a clue about the true application of the towing and capacity numbers. Their usual first thing they come out with when you have any diesle truck is ....with that beast you can tow anything we have on the lot....not correct.

 

Ken