The rules and regulations cannot be completely set aside when writing about various tire fitment situations. Because so and so knows there are other parameters involved doesn’t make it so without the approval of the ruling bodies. Basically the DOT regulations were written for vehicle manufacturers to abide by. That luxury is not passed on to the consumer to do with as they see fit. There are so many hands in the regulations pot it’s very hard to sort them all out and find common ground. It takes them, on average, five years to make firm changes to already existing regulations. How far above “red line” can we go before things start failing? Most will say you’ll know it when you get there. In the case of tires they may just POP.
NHTSA, the safety arm of the DOT, writes and enforces vehicle safety. That includes the tires they ride on when applicable. Yep, here it comes, I’m always spouting it and sometimes it sinks in. NHTSA’s safety statement about replacement tires is simple and easy to understand. “Use replacement tires the same size and load capacity as those found on the vehicle tire placard, certification label, or in the vehicle’s owner’s manual.” Seek assistance from the vehicle manufacturer or the maker of the OE tires. I can post a page full of references from tire manufacturers that fully support that safety requirement. Unfortunately they cannot control what their retailers will do.
People like to read regulations to a point where they are satisfied and stop. Their out of context solution in regards to the RV trailer axle is, replacement tires only have to match the axles GAWR. Oops, NHTSA saw that coming and wrote the above safety standard. Another one is the OE tires only apply to the first sale. Well that’s true, the above NHTSA standard allows for a wide selection of replacement tires, just as long as they provide the minimum load capacity found on the vehicle’s tire placard.
Say you walk into a large well established tire retailers place of business with a couple of trailer rim/tire assemblies in hand and want replacements. If you are up front with them and identify the vehicle’s tire placard requirements, you should then be presented with a selection that will satisfy the needs of the tire placard. If asked to accept something less than minimum placard requirements and their story is “they are better” or “they will work” ask for full disclosure on the bill of sale.
Because load capacities are so different among the tires available for RV trailer service the selection process for replacements can become very complicated. Especially if your RV trailer is small enough to consider Passenger (P) tires. Then there all the double standards to consider. Most first time RV trailer users are not familiar with tire fitments that do not have to provide some sort of reserve load capacity. Why would anybody ever want to haul around an RV trailer on tires without any reserve load capacity? Our history of keeping our tires properly aired will never support such a condition without numerous failures.
Food: Do you know that the RV trailer manufacturer MUST record the tire ID numbers for each tire on your trailer and keep them on file for five years?
FastEagle
p.s. I see that while writing this, tireman9 was also posting. I wish I had access to those manuals. My wife might jump ship if I purchased them….LOL
