Originally Posted by 1bigmess
Proof of industry-wide acceptance of load tables please? That's what I'm asking for.
This is serious business right here. It affects safety, longevity, overall usefulness of a product and what it is suited for. This is not an area I am gonna fool around in, especially when it comes to my safety and my wallet. If the load tables for my size tire and load range as stamped on the sidewall are accepted industry wide, then running at the suggested load table pressure (less than max pressure for the ST tires on my trailer) for my actual tire loadings will not void any warranty by not properly inflating the tire no matter whose load table I'm reading.
I only ask for proof of the claim you made. If you have it, great. A link would be nice so I can see it myself. If you can't, just say so, and this is over. After all, there is a lot at stake with improper loading and inflation of tires on vehicles on public roads, wouldn't you agree, and just taking someone's word isn't good enough?
To give a complete answer to your primary question would be quite lengthy and incomplete if I were to write it. Mainly because I’m not a member of the Tire & Rim Association. Their manuals are - in part - confidential and only members can purchase them new. Even used ones are expensive and not really necessary for the layman information I provide on my tire/rim postings.
I’m going to include a document from another contributor to tire industry standards and regulations. It’s from the Rubber Manufacturer’s Association (RMA). Even it’s references to the TRA manual is old (2004) and does not address trailer tires so the steel cased LT235/85R15G is not found because it’s a trailer tire.
If you go to the online Goodyear load inflation PDF you will see that it’s also old (2005) and does not include major changes implemented on the 2007 NHTSA rules changes.
In this RMA reference you will find that even the RMA has included TRA information they asked permission to print.
The bottom line is; vehicle owners use load inflation charts because they can be found on the internet. But for what reason? Vehicle owners do not set recommended tire inflation pressures.
Vehicle manufacturer’s are the only ones authorized to set Original Equipment recommended (correct) cold tire inflation pressures. Here is what the regulation says. Tire fitments: The size designation and the recommended cold inflation pressure for those tires such that the sum of the load ratings of the tires on each axle is appropriate for the GAWR.
That short statement sets the standard for that vehicle and all subsequent replacement tires.
Tire industry standards, the TRA & RMA do not recommend design changes with replacement tires. The may support plus sizing but will always ask the owner to first seek recommendations from their vehicle manufacturer.
Remember, all Automotive tires and RV trailer tires are fitted in accordance with the same FMVSS regulations (standards), and with few exceptions are identical.
Note: Rims are certified by the SAE.