Normally I spend, on average, about three hours a day researching my hobby, tires. When regulations and standards are updated I replace the older ones in my data base with the newest ones. Today it’s tire identification. The new CFR is dated 1/4/19 and is included below.
Throughout all the forums I follow, there is always someone posting how they talked their dealer into replacing the tires on their new – from the factory – RV trailer?
I’m going to first quote from FMVSS. It has very stern and specific directions to the trailer manufacturer and the dealer, that says in part that the tires on the trailer at the time of first sale MUST be the same designated size as those described on the trailer’s certification label. There is wiggle room there but not much. A designated size (ST225/75R15) does not include a load range. If there is not a load range described on the vehicle certification label, then the recommended inflation pressure provides the minimum load capacity the OE tires must provide. So, a LRD could be replaced with a LRE and comply with the certification label. Tire size designation is not tire brand sensitive.
Tire size options approved by the vehicle manufacturer would not present a dealer with a problem because the trailer manufacturer would be receptive to changing the certification label for an option they approved in advance. However, they would be required to insure the optional tires serial numbers are sent in for record keeping.
That leads me into tire identification. Here I’m going to quote verbatim from the reference. “Each motor vehicle manufacturer, or his designee, shall maintain a record of the new tires on or in each vehicle shipped by him or a motor vehicle distributor or dealer, and shall maintain a record of the name and address of the first purchaser for purposes other than resale of each vehicle equipped with such tires. These records shall be maintained for a period of not less than 5 years from the date of sale of the vehicle to the first purchaser for purposes other than resale.” Those records contain the tires serial numbers. Now, those rules may not be binding on the purchaser but they surely are for the manufacturer and his dealers.
https://www.ecfr.gov/cgi-bin/text-id...#se49.7.574_19