Here's something I couldn't figure out. The tire I ultimately was most interested in was the Falken Wildpeak AT4W, however I determined the LT size was going to be too large physically to work without modification. However what I thought was strange was that the 265/60 is XL rated, while the 265/65 is SL rated, yet if you compare their load indexes, they're identical. Why would one be XL and the other SL?
You need to check max pressures. Load index is based on MAX inflated pressure. A SL rated tire may only be rated for 30 psi, whereas XL is rated for 45.
XL tires behave like floatation tires in that load rating increases with pressure. So you can safely ride on lower pressures for less load, and inflate for higher load. SL tires need to be at the correct pressure or will be damaged and can blow out.. or just wear like **** because they’ll be under inflated.
SL rated tires cannot meet the pressure required, and therefore the OEM load rating.