As some of you here know, I stretched our original 2007 PC Michelin LTX tires to 14 years. They looked like 6 years old when I changed them out. I just wasn't comfortable going one more year with them.
I don't recommend people doing what I did. Our situation is unique in that our PC is stored in a climate controlled garage, and our model 2350 without a slide-out is not carrying as much weight as a typical motorhome, hence we run at lower tire pressures than most people.
For the curious.....
Here was the condition of our original 14 year old Michelin tires with manufacturing date codes of December 2006.
You can see little cracks forming near the steel wheel in the area of the date code.
Since I also changed to Alcoa wheels, I sold 4 original tires and steel wheels (all rears) on Craigslist for $400.
The wheels were still like new after 14 years. The tires still had a lot of good even wear thread.
Shown here are the Alcoa wheels delivered.
Each wheel weighs exactly 20 pounds less than a steel wheel with simulators.
Here they are installed.