Door Post Weight Limits

[ctbruce]

Probably going to stir the poo pot up just a little, but hey, isn't that what forums are for? Well, at least some of the posts I read that seems to be the intent!

This is an honest question that I'm hoping someone will know the answer to. If you want to speculate or give an IMHO answer go for it, but state it is IMO.

Question: are the weights posted on the sticker an absolute value that cannot/should not be exceeded or are they an estimate with a little wiggle room built in to account for Bubba who will exceed the numbers?

I ask because many things have a fudge factor built in. Take medication expiration dates for example. Almost all meds are still usable 1 year after the posted expiration date, per a Department of Defense study. So I wonder are the weight stickers similar?

Go....

Chip Bruce, RPh
Kansas City, MO
2016 Fuzion Impact 312
2015 Chevrolet Silverado LTZ
WELL....THAT WAS FUN!

[2014301ktmhauler]

Yes. You can add the boat trailer to your 5th Wheel.

[CWSWine]

Safety is critical when towing an RV Trailer. This training video discusses the importance of understanding a Truck's ratings and how these ratings limit the size of the trailer that can be safely towed. You will be provided the tools and basic understanding needed to assist your endeavor to properly match a truck and trailer, so that you can enjoy RVing safely.

http://rvsafety.com/rv-education/mat...ks-to-trailers

[xcntrk]

You have to understand what goes into the numbers in order to determine if you can exceed and by how much. Let's take the rear gross axle rating for example. On my rig, a single rear wheel truck, the RGAWR is 7000#. That number is made up of the lowest maximum rating of each component in the rear axle stack. Tires, Wheels, Springs, and the Axle housing itself. Each has a different max rating, but the 7k limit is set by the lowest of those components, being the springs my case. So lets say you bolster the springs with air-bags effectively moving up that maximum rating, the next lowest component in the stack becomes the limitation - and so on. So to my point, you really need to understand what makes up a maximum weight rating so that you can determine if (and how) it can be exceeded.

Same is true for the trailer with a 5th wheel being a good example. My trailer has a GVWR of 17k pounds, but the unit is only equipped with tandem 7k pound axles. The presumption is the other 3k pounds is on the pin and therefore not supported by the axles. BUT that said; you have to be careful not to overload the garage or you can easily exceed the axle maximums putting too much weight in the rear of the rig without the proper distribution on the front.

[CWtheMan]

Originally Posted by xcntrk

My trailer has a GVWR of 17k pounds, but the unit is only equipped with tandem 7k pound axles. The presumption is the other 3k pounds is on the pin and therefore not supported by the axles. BUT that said; you have to be careful not to overload the garage or you can easily exceed the axle maximums putting too much weight in the rear of the rig without the proper distribution on the front.

The axle manufacturer’s certification label affixed to the individual axle may match the certified GAWR value on the certification label, but, the GAWR may be lower because the vehicle manufacturer must get the numbers on the federal certification label to equal out. They are the official load capacities for the trailer.

It’s all a matter of knowing the FMVSS standards the vehicle manufacturer MUST build to. An example can be found in FMVSS 571.120 paragraph S10.2; “On RV trailers, the sum of the GAWRs of all axles on the vehicle plus the vehicle manufacturer's recommended tongue weight must not be less than the GVWR. If tongue weight is specified as a range, the minimum value must be used.” Once the trailer manufacturer has used that published tongue weight to balance out the trailer it becomes the responsibility of the trailer owner to manage the tongue weight.

Here is another bit of information I found in a NHTSA Q & A document.

“The FMVSS have requirements for the manufacturer to use proper tires and rims for the gross axle weight rating (GAWR) and the gross vehicle weight rating (GVWR). The manufacturer may determine the GVWR by adding cargo capacity (if any) to the curb weight of the vehicle as manufactured. The wise consumer, before purchase, will determine if the vehicle has sufficient cargo capacity to carry the weight of water, additional equipment (such as televisions, and microwave ovens), and luggage. The manufacturer’s certification label must show the GVWR. The GVWR must not be exceeded by overloading the vehicle. There is little the government can do to assist a consumer who has purchased a vehicle that has insufficient cargo capacity for its intended use.”

[CWtheMan]

Originally Posted by xcntrk

You have to understand what goes into the numbers in order to determine if you can exceed and by how much. Let's take the rear gross axle rating for example. On my rig, a single rear wheel truck, the RGAWR is 7000#. That number is made up of the lowest maximum rating of each component in the rear axle stack. Tires, Wheels, Springs, and the Axle housing itself. Each has a different max rating, but the 7k limit is set by the lowest of those components, being the springs my case. So lets say you bolster the springs with air-bags effectively moving up that maximum rating, the next lowest component in the stack becomes the limitation - and so on. So to my point, you really need to understand what makes up a maximum weight rating so that you can determine if (and how) it can be exceeded.

Whenever there is excess GAWR for automotive vehicles it's considered "reserve load capacity". The bottom line is the vehicle's GVWR. Vehicle manufacturers will not recommend exceeding GVWR.

[SAABDOCTOR]

I have been weighted in Connecticut. the weight on the door jamb is the law to a leo. can you exceed it? most likely but your insurance company and the people that are sueing you after a crash will have a field day with you if you exceed that weight. Here is a gray area to consider. If you change a component to raise the weight limit who is responsable for the certification of that increase? ford chevy toyota chrysler will not back you up unless it is their product. the aftermarket... well your on your own. imho it just is not worth loosing everything i have worked for. Stay safe stay legal.

[CWtheMan]

Originally Posted by SAABDOCTOR

I have been weighted in Connecticut. the weight on the door jamb is the law to a leo. can you exceed it? most likely but your insurance company and the people that are sueing you after a crash will have a field day with you if you exceed that weight. Here is a gray area to consider. If you change a component to raise the weight limit who is responsable for the certification of that increase? ford chevy toyota chrysler will not back you up unless it is their product. the aftermarket... well your on your own. imho it just is not worth loosing everything i have worked for. Stay safe stay legal.

Only the vehicle manufacturer or a certified vehicle modifier have the authority to change GVWR.

[xcntrk]

Originally Posted by SAABDOCTOR

I have been weighted in Connecticut. the weight on the door jamb is the law to a leo. can you exceed it? most likely but your insurance company and the people that are sueing you after a crash will have a field day with you if you exceed that weight.

How would that be determined in an post-accident investigation?

All gross violations aside; it's not practical to determine if a vehicle is loaded over the manufacture limit without weighing it. And even then you would need to weigh the TV and trailer separately. But even armed with this information; a prosecution would need to determine fault AND link that fault to towing while over-loaded.

[chuckster57]

There isn't any fudge factor built in if you get weighed. 1 pound over can get your stuff impounded and you don't get it back until you show up with a TV rated for that load.

[xcntrk]

Originally Posted by chuckster57

There isn't any fudge factor built in if you get weighed. 1 pound over can get your stuff impounded and you don't get it back until you show up with a TV rated for that load.

By whom?

I have never seen a private hauler weighed and in most states they only care about your weighted registration (plate) to ensure you're not exceeding what your registered to haul (note this is not for safety but for taxation purposes). If you're towing under 24k, the only requirement is to be registered for the weight being towed. Manufacture limits mean nothing (gross violations aside). Now if you get in an accident and harm somebody, I'm sure a negligence investigation could be made and manufacture limits might come into play...

[ctbruce]

Please note, I'm not trying to exceed maximums. That is not the point. I'm wondering if the maximums are absolute maximums (1 ounce over and you will break down, void your insurance coverage or sway wildly out of control and cause a serious accident) or are they agreed upon maximums that are a percentage below the absolute maximum to provide a margin of safety built into the system to protect us from ourselves?

So, no I don't have a boat to pull behind my 5th wheel which I also do not have. I understand the weakest link being the limiting factor, and I'll watch the video provided, I just haven't yet. Thanks.

Chip Bruce, RPh
Kansas City, MO
2016 Fuzion Impact 312
2015 Chevrolet Silverado LTZ
WELL....THAT WAS FUN!

[RGene7001]

I would say that GVWR is a hard, officially certified number which should not be exceeded, there are laws in many states against it.
The sum of axle ratings may be slightly higher than GVWR but its difficult to exceed axle weights unless weight distribution is poor or nonexistent or the vehicle is grossly overloaded.
Cargo carrying capacity may or may not have some wiggle room, it depends on the manufacturer, presence of aftermarket or optional equipment. Knowing your actual weights is important.
Towing capacity is marketing tool, mostly meaningless.
Lawyers will suck out your insurance coverage to the limit regardless of the fault, at least in my state. This is what they do for living.

[roadglide]

Originally Posted by RGene7001

I would say that GVWR is a hard, officially certified number which should not be exceeded, there are laws in many states against it.
The sum of axle ratings may be slightly higher than GVWR but its difficult to exceed axle weights unless weight distribution is poor or nonexistent or the vehicle is grossly overloaded.
Cargo carrying capacity may or may not have some wiggle room, it depends on the manufacturer, presence of aftermarket or optional equipment. Knowing your actual weights is important.
Towing capacity is marketing tool, mostly meaningless.
Lawyers will suck out your insurance coverage to the limit regardless of the fault, at least in my state. This is what they do for living.

Thank you for the informational about florida.

[roadglide]

I know on my 2500 the 20 inch OME tires are the weak link . There almost new but that doesn't make it right . Chevy with the 20,s make it hard to fit higher pay load. Discount tires swear I can put 285/60/20 with pay load of 3650 a nice step up from the 3150 stock OME tires. MY year Duramax that was one way chevy downed the GVW ,The spare tire is is 18 inch I cant remember the size but its the same fit as the OME 20, the 18 has load range of 3650 lbs.

[Desert185]

I am not an engineer.

IMO, engineers design components and complete structures to be more robust than the stated ratings in order to have a margin for failure. What the particular margin is depends on the structure itself.

If you exceed the posted limits by a limited amount (and that amount is certainly unknown by the consumer) you will not break anything or lose control. The legal and moral aspect of doing that has already been expressed more than once on this forum, so I won't revisit those concerns. (You're welcome )

[kfxgreenie]

Originally Posted by roadglide

I know on my 2500 the 20 inch OME tires are the weak link . There almost new but that doesn't make it right . Chevy with the 20,s make it hard to fit higher pay load. Discount tires swear I can put 285/60/20 with pay load of 3650 a nice step up from the 3150 stock OME tires. MY year Duramax that was one way chevy downed the GVW ,The spare tire is is 18 inch I cant remember the size but its the same fit as the OME 20, the 18 has load range of 3650 lbs.

Check out the Nitto's if you can get them in the wheel well they have some good weight ratings. I run a 295 60 20 G2, 3750lb's plenty of reserve capacity on a 20" wheel.

http://www.nittotire.com/light-truck...ht-truck-tire/

I'm actually more limited by my wheel's at 3500 LB's Each

https://www.racelinewheels.com/p-924...-hd-8-lug.aspx

[chuckster57]

CHP does weigh private parties. On my Ford truck forum we just had a thread and a member stated that it does happen in Texas. My wife's son has seen it in person at Pismo Beach.

[xcntrk]

Originally Posted by chuckster57

CHP does weigh private parties. On my Ford truck forum we just had a thread and a member stated that it does happen in Texas. My wife's son has seen it in person at Pismo Beach.

Are they measuring against your registered weight or the manufacture limits?

In Virginia any vehicle exceeding 7500# have to move to a "weighted" plate. At that point its up to the owner to determine how much weight they're going to register. If you're ever stopped and towing on a non-weighted plate or towing a load in excess of your registered limit, this is where you can get hit with penalties and excessive fines. But again this isn't the highway patrol checking the safety of your vehicle to determine if you're within some magical manufacture limits; instead this is a check to ensure you're registered and entitled by the state to tow at the limit observed. (aka that you've paid the man in order to tow the load you're exerting on the state roadways).

[chuckster57]

Originally Posted by xcntrk

Are they measuring against your registered weight or the manufacture limits?



In Virginia any vehicle exceeding 7500# have to move to a "weighted" plate. At that point its up to the owner to determine how much weight they're going to register. If you're ever stopped and towing on a non-weighted plate or towing a load in excess of your registered limit, this is where you can get hit with penalties and excessive fines. But again this isn't the highway patrol checking the safety of your vehicle to determine if you're within some magical manufacture limits; instead this is a check to ensure you're registered and entitled by the state to tow at the limit observed. (aka that you've paid the man in order to tow the load you're exerting on the state roadways).

Registration seems to vary by state. Here in Ca if you drive a truck, it will have commercial plates and you will pay a "weight fee" based on GVWR. The case I cited from Pismo involved weighing the rear axle and the RAWR printed on the door sticker. My '94 F350 has a GVWR of 10,000 lbs. and I paid $186.00 in "weight" fees.