Weighed Rig At Scales Today... Now What?

[Buyer2021]

This is why, even for HDs, you'll probably see payload capacity being greater than tongue weight. Payload capacity is, theoretically, the maximum weight that can be applied between the front and rear axles of the tow vehicle.

Do yourself a favor, quit while you're ahead.

Payload rating will always exceed a given rated tongue weight limit, there is no particular relationship between TW (which is hitch-limited) and Payload (which is suspension / axle limited).

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[Samson16]

You're making a big assumption there.

Not really.

OP reported this:
Trailer Both Axles - 4431lbs

If the tongue weight of that tandem axle trailer is anywhere close to 1000lb as loaded it's the worst designed trailer since Monty Python tried sneaking into that castle.

 

[Samson16]

Now if he means 4431 each axle then his trailer is over loaded and that's his problem!

If his 7000lb trailer weighed in close to 9000lb then...

 

[Davexxxx]

Not really.

OP reported this:
Trailer Both Axles - 4431lbs

If the tongue weight of that tandem axle trailer is anywhere close to 1000lb as loaded it's the worst designed trailer since Monty Python tried sneaking into that castle.

Yes really.

The camper we ordered.
HITCH WEIGHT590 lb.UVW5,313 lb. = 11.1% TW naked.

https://forestriverinc.com/rvs/travel-trailers/surveyor-legend/252RBLE/4853

Random selection from a different brand.

HITCH WEIGHT570 lb.UVW5,328 lb. = 10.6% tw naked.

Different random selection, from yet another different brand.

HITCH WEIGHT685 lb.UVW6,196 lb.= 11% tw naked.

Different family all together. I looked hard at this one.

Hitch 690

UVW 6,845

= 10.1% tw naked.

https://www.granddesignrv.com/travel-trailers/imagine/2670mk


Now, considering that these don't count propane, or the batteries, or anything in the passthrough storage, all of which are in the front. You can bet long green, that these percentages will rise.

 

[UGADawg96]

Never trust RV manufacturer listed dry and tongue weights. It would be like if Ford published the curb weight of the XL for King Ranch and Platinum trims.

 

[Samson16]

OP's trailer has a GVWR of #7554.
Your highest tongue weight % example was 11.1% which gives OP 838.5lbs. tongue weight with max trailer weight.

He can safely tow that much trailer. He overloaded the bed with extras that pushed him 39lbs. over rear GAWR.

 

[Samson16]

Never trust RV manufacturer listed dry and tongue weights. It would be like if Ford published the curb weight of the XL for King Ranch and Platinum trims.

True. For InTech they over report just a bit. 700lb TW is generally 650lb or so.

 

[Polo08816]

Do yourself a favor, quit while you're ahead.

Payload rating will always exceed a given rated tongue weight limit, there is no particular relationship between TW (which is hitch-limited) and Payload (which is suspension / axle limited).

In 1 ton SRW and definitely in DRW configurations, tongue weight is likely to be more hitch receiver limited than suspension/axle limited.

Take the GM HD 2500/3500 platform. Both platforms, regardless of whether it is gas/diesel or SRW vs DRW, actually use the same hitch receiver part number:

https://www.gmpartsdirect.com/oem-p...wLWhkJnk9MjAyMSZ0PWRlbmFsaSZlPTYtNmwtdjgtZ2Fz

Yet they have different bumper tow trailer weight capacities:

https://gmauthority.com/blog/2022/12/here-are-the-2023-gmc-sierra-hd-towing-capacities/

Obviously without having easy access to a lot of trailering data plate on actual vehicles, there are a lot of inferences to make here.



However, in 1/2 ton and 3/4 ton trucks, I think the tongue weight is likely to be suspension / axle limited.

The force that is applied to rear axle of a pickup is greater than the force that is applied to the hitch receiver by the tongue of a trailer due to the lever effect.

2 inch Class 4 hitch receivers should be rated up to 1400 lbs of tongue weight when used with a weight distribution hitch. That means that at some point, the hitch receiver has the capability to take a 1400 lbs static load (prior to you setting up the WDH mechanism).

I guarantee you that 1400lbs of static load applied to the hitch receiver will exceed the Rear Axle Weight Rating of any F150 that does not have the Heavy Duty Payload Package.

Remember, the available rear axle capacity is certainly less than the payload capacity of the entire vehicle because payload capacity is the total of the available capacity for both the front and rear axles.

 

[Davexxxx]

OP's trailer has a GVWR of #7554.
Your highest tongue weight % example was 11.1% which gives OP 838.5lbs. tongue weight with max trailer weight.

He can safely tow that much trailer. He overloaded the bed with extras that pushed him 39lbs. over rear GAWR.

Yes, we agree, with some shifting weight around and dialing in his WDH, the OP can achieve his goal, with room to spare.

My point was that assuming a 10% tw, even straight from the factory, is not a safe assumption and on a 7500 GVWR trailer, going from 10% to just 11% is 75 lbs. on trucks where that could matter.

 

[Samson16]

Thanks for the back and forth. I'm a bit of a grinder lol.

 

[Snakebitten]

I wonder what happens if you are at exactly 1 lb under the max weight rating of the rear axle, and then stop and grab a Big Gulp?
Do you have to sit in the front seat?

Actually, I wonder what the engineering headroom is on the various components that make up the arrived at Payload rating.

I'd be more concerned with distributing the weight where physics favors stability rather than focusing on 39 lbs. Or put another way, I don't like how a light front axle feels. Gives me the heebyjeebys.

 

[Samson16]

I don't like how a light front axle feels. Gives me the heebyjeebys.

I can't diet honey, we've got that front axle GAWR to think of!

 

[Davexxxx]

I wonder what happens if you are at exactly 1 lb under the max weight rating of the rear axle, and then stop and grab a Big Gulp?
Do you have to sit in the front seat?

Yep. Thats what is shearing those axle bolts.

Actually, I wonder what the engineering headroom is on the various components that make up the arrived at Payload rating.

Its a witches brew, unfathomable by mere mortals and tempered by 100 yrs. of experience.

In the old days, you could sort of assume that things were over built to hold dbl. stated rating.

Those days are long gone.

Computing power, energy and materials costs, have things trimmed down to a much finer point.

Saw a show about that once, trying to explain it. Rated as individual components, then as systems assemblies and they actually trimmed some of that, without any more explanation than "We found we didn't need it".

It'd be nice if an automotive engineer could spill it.

 

[Henfield]

Thing that amazes me about this thread, is the added weight of the powerboost sytem. His unloaded weight is about 5800lbs which is about 600lbs heavier than my loaded 5.0xlt......

 

[Snakebitten]

The Powerboost is obviously heavier than a non Powerboost.
However it does have a heavier duty frame and additional GVW rating as a result.

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