Found this link on a new report from CR.
The tires tested were not ST type tires but the observations still apply.
The author thinks "Chinese manufacturing will follow the historical trend of
Japanese and Korean brand tires, which were disrespected at first but
eventually became good values in the eyes of the consumer".
I agree. I believe the current problems many are having with China made tires comes from the selection process done by the Trailer assemblers. To me it appears that for many, their #1 criteria is their initial cost. Since they don't have to worry about warranty costs some may be thinking that as long as it is round black and has the correct load capacity to meet DOT requirements it's not their problem if the RV owner has tire problems.
The challenge with tire failures is separating the "Root Cause" for a failure and learning if it is service related (overload, under-inflation and or over-speed) or if the failure is a design or manufacturing quality problem. Too often RV owners forget that running a tire under-inflated a few months before the actual failure is the primary cause of the failure.
While on vacation I met a 5th wheel owner and of course the talk eventually turned to tires. He admited having tire problems in the past so claimed to be paying more attention to his new RV and its tires. The problem was he also admitted to having towed the trailer with only 35 psi in the tires but since he has now inflated the tires to their more proper 80 psi he was certain all was OK.
After a little more discussion it was obvious he was not receptive to the possibility that he might suffer a failure in the future because of his past actions.
I think the BOTTOM LINE on the CR report is that "some" China made tires do not perform as well as tires made in other countries. HOWEVER there are also "some" China made tires that are competitive with the rest of the market.