Quote:
Originally Posted by CWtheMan
Sorry Tireman9, My goal is to write it the way it's supposed to be, not to what is good for the goose. Most of the current standards were approved in 2007. However, NHTSA and the tire industry keep safety standards current with bulletins, addendums and such.
As I said earlier, the trailer manufacturer is solely responsible for OE tires. Because the FMVSS enforces minimum standards, OE tires are considered a minimum guidance for replacements. Because NHTSA and the tire industry have reinforced tire descriptions, any prefix in the tire size description (P, LT, ST) is part of it's official size description. When the vehicle certification label reads ST225/75R15 the ST tire design is locked-in because of vehicle certification and numerous other NHTSA/tire industry standards.
Is it unsafe to use tires that are from a different design to replace your trailer tires? Probably, if you follow the established tire industry standards for such replacements. However, IMO, if such replacements were ever investigated for safety violations the plus sized tires would be a misapplication if not recommended by the vehicle manufacturer for that fitment.
There are always exceptions and arguments. An exception would be a tire with a LT prefix in it's size designation but is clearly designated by it's manufacturer as being for trailer service only and that info is molded onto its sidewall.
A strong argument could be won when 225/75R17.5 sized tires are used and they were designed for low platform trailer service.
|
Key word is "minimum" requirement.
Should we interpret your position to mean that if someone had a 2015 RV with an ST225/80R16LR-E but the 2017 model of the same RV with the same GVWR comes with LT235/85R16 LR-G you would say it is incorrect for the owner to go to the LT235's because that was not the size originally approved?
I am not aware of any RV company or car company issuing bullitins suggesting new or better tires on older model trailers. Doesn't the Navy do updates?
If the owner increases the load capacity of the tires please give us the technical reason why this would be bad or why it would not improve the safety of the RV as with going from 0% margin to 10% margin would clearly be an improvement IMO.
If you disagree then I guess folks will need to decide if they want to listen to an actual tire engineer or someone with just an interest in tires