Just posting to say I'm glad I found this thread. Maybe I'll find some time to read the posts on pages 2 - 43. My new to me '15 LX570 came with new 275/55-20 LTX M/S2 in XL rating. I did just get a matching spare installed at Costco as well because the spare that was under there was the original, 12 year old Dunlop in 285/50-20 form. Seeing details on this thread makes me less nervous about towing my 5K lb TT with a 700 lbs tongue weight (and WDH) as well as people's experiences with moderate off-pavement excursions. I make annual trips to the San Juans and run trails like Clear Lake, Alpine Loop, Imogene, Black Bear, etc. I've been a little worried about the tire's ability to withstand the sharp rocks because I'm used to BFG KO2s Load Range E on my LC100.