I have approximately 20,000 miles on these Sailun tires. I am having some arguing issues with myself on changing them out. As with a lot of the Sailun's the outside and inside groove is wore down. I have seen this on several units. But the rest of the tread is looking good yet and it tells me not to change. The tires is an LT235/85R16, which with it being said that its a LT with higher speed ratings, but then it's stamped for trailer use only. Not that I want to travel over 65 because I don't but like most everyone else I travel at about 62 which means I am close to max speed. I don't want to skimp when it comes to the trailer, but I also don't want to waste the remainder of this tire life. Just come to my attention, with this being a 2011 these tires are at least 3 yrs old and probably older. Hmmmm another thought! Dave