5th wheel towing capacity

[wakamicamper]

First off, I apoligize if this question has been asked before.

I read an article in a magazine called RV Lifestyle that states that the towing capacity of all trucks of the big 3 are set by the Marketing department and not by the engineers.

I have just ordered a 2010 GMC Sierra CC 8' box 4x4 diesel. The towing capacity for the DMax for this truck is 13000 lbs. for the 2010 model year. In 2009, it is 12700 lbs. , and for 2008 and 2007, it is 12500 lbs. There hasn't been any changes to the springs, axle or frame since 2007, so I am now wondering what this truck can really tow that the Marketing people are not telling us?

I have been able to confirm that the frame used by GMC and Chevy is the same for both the 2500HD and the 3500HD (Same part number)

The rear axle has a gvwr of 6900 lbs. while the springs are rated at 6084 lbs. Why is the spring capacity so low as compared to the axle capacity?

I have read that the only difference between the 2500 and 3500 is the springs. If this is true, then why does a 2009 3500HD SRW CC 8' box 4 x 4 diesel have a towing capacity of 14800 lbs. and a GVWR of 9400 lbs?
I also find it interesting that in the model years for 2007, 2008, 2009 and 2010 that the truck with the diesel can tow 13000 lbs. regardless of whether the truck is 2WD or 4WD or if it is a reg cab, ext cab, or Crew Cab.

Does this strike anyone else on this board as strange? Am I missing something or are our trucks built better than we are being told?

[TXiceman]

This is an age old discussion. So much of the tow ratings is marketing hype and it is hard to sort through the hype to get to the real meat of the issue.

Basically the tow rating present are pure hype as they generally try to maximize the rating to make then look bigger or better than the other guy. Mostly the manufacturers use a stripped abse model truck to get a low curb weight and then work up the numbers.

In the real world you need to work from three numbers...GCWR, GVWR and Laden Vehicle Weight. The Laden vehicle weight (LVW) is what your truck weighs, loaded with fuel, cargo and passengers.

The GCWR or gross combined weight rating is the maximum the truck and trailer can weigh in total.

The GVWR is the maximum weight your truck can be as a total weight on it's two axles.

The GCWR is noted in the owners manual for a marticular cab/engine/axle and 2 or 4 wheel drive.

The GVWR is located on the drivers door jamb sticker. There are also GAWR numbers for the front and rear axles.

To determine what you can pull within ratings....

GVWR - LVW = Maximum loaded trailer pin or tongue weight. A typical 5er will put about 20% of the trailers GVWR on the pin and hitch. This adds directly to the trucks two axles...mostly the rear axle.

GCWR - LVW = Maximum loaded trailer weight allowed.

The real issue is a diesel. a DRW and a 4 wheel drive truck, all weigh more than the base model and therefore cannot pull as much trailer.

A 3/4 ton truck does not have as much GVWR rating and can ot take as much pin weight as can a DRW truck.

So in figuring just what you can tow within ratings, it is a two part formula...you need to meed both GVWR and GCWR for the truck.

You can also look at GAWR for the truck and tire loading or ratings.

So the manufacturers tow ratings are an optimistic starting point. Basically, I would look at the number as a good 80% or the rating starting point. Then you need some weights and do the math.

Remember....NEVER believe the RV or Truck sales person.

Ken

[Ti5er]

TXiceman, I've seen arguments over this subject and friendships strained to the limit with this subject. Of All I have heard and read I must tell you that's undoubtedly the best I have ever heard it answered, kudos to you.

[powerboatr]

Quote:

Originally Posted by TXiceman This is an age old discussion. So much of the tow ratings is marketing hype and it is hard to sort through the hype to get to the real meat of the issue. Basically the tow rating present are pure hype as they generally try to maximize the rating to make then look bigger or better than the other guy. Mostly the manufacturers use a stripped abse model truck to get a low curb weight and then work up the numbers. In the real world you need to work from three numbers...GCWR, GVWR and Laden Vehicle Weight. The Laden vehicle weight (LVW) is what your truck weighs, loaded with fuel, cargo and passengers. The GCWR or gross combined weight rating is the maximum the truck and trailer can weigh in total. The GVWR is the maximum weight your truck can be as a total weight on it's two axles. The GCWR is noted in the owners manual for a marticular cab/engine/axle and 2 or 4 wheel drive. The GVWR is located on the drivers door jamb sticker. There are also GAWR numbers for the front and rear axles. To determine what you can pull within ratings.... GVWR - LVW = Maximum loaded trailer pin or tongue weight. A typical 5er will put about 20% of the trailers GVWR on the pin and hitch. This adds directly to the trucks two axles...mostly the rear axle. GCWR - LVW = Maximum loaded trailer weight allowed. The real issue is a diesel. a DRW and a 4 wheel drive truck, all weigh more than the base model and therefore cannot pull as much trailer. A 3/4 ton truck does not have as much GVWR rating and can ot take as much pin weight as can a DRW truck. So in figuring just what you can tow within ratings, it is a two part formula...you need to meed both GVWR and GCWR for the truck. You can also look at GAWR for the truck and tire loading or ratings. So the manufacturers tow ratings are an optimistic starting point. Basically, I would look at the number as a good 80% or the rating starting point. Then you need some weights and do the math. Remember....NEVER believe the RV or Truck sales person. Ken

HMMM
very nicely stated
100%

[TXiceman]

Rather than making passionate post about I pull this or that and no problems, we prefer to provide the facts and calculation methods, encourage weighing rigs and let the person make up their mind about what to do.

Thanks for the flowers....

Ken

[450Donn]

When did Government Motors up the 3/4 ton GVWR from 9200?
IMHO yes it is market driven. But on the other hand if that is the numbers that the manufacturer warrants their vehicle to the feds as performing as stated, why do so many people ignore that and simply load them up however they think is OK?
To answer your original question, tires and wheels are also in play between the 2500Hd and the 3500 SRW versions. After being suckered into the smaller is better scheme of things I will always advise a person to buy the biggest truck he can afford. that way there is no mistaking the fact he has enough truck for the load we drag behind them.

[RustyJC]

The "manufacturer's trailer tow rating" is theoretically computed as the truck's GCWR minus the truck's curb weight. The problem is that the manufacturer can play games with the curb weight as the small print defines it as a base truck with a 150 lb driver.

In my case, the curb weight for a Cummins-powered Dodge 3500 extended cab long bed dually used by the manufacturer in this calculation was 6100 lbs. I daresay that there's never been a 2nd generation Cummins-powered extended cab dually built that's within 500 lbs of that number, and that's being generous. The actual laden curb weight (LCW) of our truck is 7680 lbs, so the difference between the 7680 lbs and 6100 lbs represents the marketing fluff in the so-called "trailer tow rating".

Rusty

[wakamicamper]

Thank you for the replys. 450Donn, The 3/4 ton is still 9200 GVW, the 9400 is on the 1 ton.
The magazine where I saw the article is in RV Lifestyle Vol 38 #4. Letters to the techno weeny. Hi quote is this:

"The tow ratings are set by the marketing department, not the engineering staff. and they are always conservative, bit it is wise to stay within the recommendations to avoid any warranty issues".

[450Donn]

Again unless it has been changed down, the 1 ton SRW GM product has a 9900 pound GVWR.
Over on another forum is a fella who used to do the certification stuff for GM and he explained it pretty well a few months ago.
Basically the GVWR ratings as posted on the driver door post is a statement to the federal government by the manufacturer stating that the vehicle will perform in all situations, acceleration, braking, accident, accident avoidance up to the posted gross weight rating the same as if it was empty. It has no bearing on anything except in some states licensing. Those states sell tags based on what you as the owner wants to buy. The heavier the more it costs you.
Personally the number is there for some reason. I have towed with a 3/4 ton GM product that scaled loaded ready to camp at 7500 pounds and hitched at 10,500 pounds. It is no fun trying to wrangle that load on a truck chassis that is not designed to handle it. Two years was enough for me. And it took that long because of economic conditions. I actually knew by the second trip we made.
Like I said before it is your decision what value you place on your families safety and your sanity.

[wakamicamper]

My apologies to the board, I misread the 1 ton GVW as 9400 when it is 9900. What I read was the max trailer weight with the 6.0 L engine on the K30943 Crew Cab SRW 8' Long Box 4x4 with the 3.73 axle. With the Dmax the max trailer tow is 13,000 lbs. While the max towing with a 5th wheel on this model is 14800 lbs. It is very easy to misread and misinterpret what is printed in the brochures.

[Frankenstien]

I think it is VERY MUCH Marketing Driven... or to put the facts in perspective...
I have a F-350 DRW Truck GVWR or 10,000 lbs Sounds impressive.... until I hit the scales... With the Winch... Stuff in the cab Fuel.. (Empty Bed) 8350 lbs that means per these #'s I would be limited to 1650 lbs of cargo in the bed. The springs BARELY begin to settle with that load. It seems that there is sincere disparegy in what is sometimes stated by the MNF and what the true ability is. I have in the past put 2 Pallets of Flagstone in the truck, Each weighing in at 3600 lbs.... or 7200 in the bed... just a bit more than that 1650.... even with that load the springs are not bottomed, and the truck accelerates and even more importantly STOPS with out any exess of effort. Now with all that said...... This is 100% opinion based, there are engineers somewhere for the big three..... insurance adjusters.... and lawyers who will tell me ... shoulda stayed under that 1650... sigh...

[wingnut60]

Wakamicamper...
Since I don't know much about GM products, curious where the spring rating came from--haven't seen that stated anywhere for Fords. And maybe the rating is PER SPRING? I'm sure there is a spring rating somewhere, just don't ever see anyone refer to it.
Thanks,
Joe

[wakamicamper]

Wingnut60

I get spring ratings from the Fleet side of the major truck builders or the commercial side of the industry. The folling web site is a listing for the Ford Fleet Superduty F250,F350, F450:

https://www.fleet.ford.com/truckbbas...50-350-450.pdf

Both Dodge and GM also have Fleet sites with similiar information. I like to know what is available before buying.

[wingnut60]

Learn something every time I read these RV forums. Never worried about spring ratings--I always take the rear axle rating to be the max load, and make sure the tires can carry that. Just assumed the springs would be rated to match everything else. Something doesn't sound right with the rating you found, but facts are facts I guess.
Thanks--never was worried enough to get past the mfg brochures/door tags for weight/tow ratings.
Joe