Replace ST tire with LT tire

[Tireman9]

Originally Posted by FastEagle

It's not there. They write in generalities. However, in 571.119 under S3 in applications the ST tire is mentioned so when qualifying tires are not mentioned specifically, that application statement would apply.

In most cases the FMVSS need to be married with tire industry standards to come to a conclusion on many fitment issues.

CFR 570.9 & 570.62 are both active regulations. And although not mentioned very often they have a significant impact on replacement tire selections and tire industry standards because they set the precedent for formal tire inspections by any authority.

Yep I agree that the Regs are not very clear but I find it interesting that some tire dealers are refusing to apply anything other than ST tires on trailers but haven't been able to provide anything in writing that supports the prohibition if the load and inflation criteria are met.
Yet here is a Federal Regulation that clearly states or at least implies that some P and LT tires are acceptable for use as replacement tires on RVs as long as the load & infl limits are considered and met.

I will check out 570.9 & 570.62 Thanks for the tip off.

I an trying to get a clarification from a person at NHTSA on this and other items. I will admit I haven't gone over all the appropriate sections of 571 for a number of years and my last foray was limited to tire markings. I did discover that there have been a few changes since 2006 that I do not understand so have sent off a request for more info.

If/when I hear back I will post on my blog and if appropriate here and some other forums too.


Sorry to the rest of the readers here if FE and I go off the deep end with the Federal Regulations but maybe you can see how tire selection can be a challenge unless close attention is paid.