TxGearhead wrote:
I could be all mixed up on this, but I THINK I have read that there is a different import duty on ST tires vs. regular vehicle tires. I believe I read that Sailun just re-branded the S637 tires to ST to avoid that. But I could be way off base on that.
You are correct on the import duty. Sailun markets two similar tires, close but not exact. The S637 is sold as an LT235/85R16 that is LT branded and has 2/32 more tread depth than the ST variant (12/32 vs 10/32). The S637 last year became available as a "Special Trailer (ST)" tire ST235/80R16. Both variants are "G" load rated, have a max speed of 75mph, and require metal stems and a wheel certified to 110psi.
It is not always simple to determine the psi rating of your wheels. Some are simply stamped with a load rating. A call to the wheels mfg. does not always get consistent results. For instance, my Forest River has HiSpec Series 9 Aluminum 16" wheels and when I called I was told they are good up to 80psi. Another owner called HiSpec and was told the very same wheel was good to 110psi as long as you added metal stems.
