You know,,, I don't know WHAT's going with tires these days.....
I too have seen the cracking sidewalls more and more (I think "dry-rot" is inaccurate and refers to old cotton based plys that haven't existed for decades
)
I replace my trailer tires every 4-5yrs even though they have 9/32nds tread left (maybe 20% used) because the sidewalls are so badly cracked. I cover them from the sun when not in use, don't use any "tire shine" on them and they still crack a lot.
I think the petroleum based tire goop people lather-on could be the cause of much of the trouble. My '05 with 27K shows no sidewall problems so maybe that's the problem with yours as who knows what the previous owner did. I use a tire shine made by Michilen that looks similar to Armor All and figure it can't hurt the tires.....
But I've also read where there are those who say tires now "expire" after a certain time (I've always chalked that up to the reactionaries among us
) and should be changed based solely on age sometimes even if you don't see anything wrong.
I think minor cracking is nothing to get too concerned about and isn't an indication of an impending, catastrophic, failure. Even badly cracked tires would probably develop leaks before they blew-out and with your TPS you'd know earlier than most
