You will have to look at each mfg website for your under coating requirements. Keep in mind someone may have a 2016 trailer with it but that doesn't mean a newer or older same unit has it or offers it.
Same with HD 16" tires.....check the mfg website online brochures and make 1-800 to their tech folks.
I have a rv trailer and several other trailers types. My last flatbed trailer came with 5.2k axles and ST 16" E load range Roadmax (another maypop ST tire).
I didn't use ST tires back (2011) then so I mounted four LT E on the wheels and sold the may pops 3 day later on craigslist to a guy with a lawn service trailer looking for cheap tires.
HD tires are easy to get after the unit is bought.
