Our watershow operation includes 11 trailers that are towed 4 days a week and we have tried lots of tires over the last 30 years. Some trailers are overloaded, some have a single axle when tandem axles would be better and a couple of our tandem axle trailers are quite underloaded
Sort of conclusions:
Chinese label tires: Nanco, Radial Trail a few other unknown names.
The Nancos replaced a set of 4 badly cracked BF Goodrich tires which had gone 20 years without a failure. We left on a 300 mile trip, 3 of the 4 Nanco tires failed in one day. Interestingly, Tires Plus that sold them too us (Yeah, great tires and we will stand behind them) immediately claimed that they were "underinflated, overloaded and driving too fast" , none of which was true. Amazing that they can tell how much air was in a tire after it blew out, or that you can divine my speed!!
Radial Trail CRT (Unknown Chinese manufacturer) These came on a new trailer that is "underloaded", 7,000 lbs of tire rating, 5,000 pound loaded trailer. Still, they all blew in the first 2 years. All have been replaced with Marathon's or their twin from Towmax, none have failed in the next 5 years.
Titan: We probably had 10 of these on various trailers, good for 2 years, then 100 percent fail rate in the next 2 years.
Marathons and their twin, Towmax: we now have about 14 of these, many up to 10 years old.
No failures ever. At least one pair of these is overloaded by 25 percent.
Car Tires: Yeah, put lots of air in them 45 lbs or more, ignore the naysayers we always have great luck with them. Many times we bought them on road trips while "trailer tires" were blowing regularly, then continued to use them. None have ever failed, I suspect the DOT test procedure has eliminated anything like the Chinese junk label trailer tires from being certified for passenger use.
Many of our Marathons are made in China, quality control and build requirements must keep them in line. I suspect that when Marathons get a bad rap its likely because they sell 50 times more trailer tires then the unknown labels and some certainly are towed "overloaded, underinflated and too fast"
Incidentally, I tried to use the DOT and NHTSA websites to report trailer tires that failed 100 percent, and received responses saying that trailer tires were exempt from reporting unless personal injury occurred as a result. Heck, I have skinned my knuckles changing them and almost got run over with flats on the interstate - but apparently that is all ok!