I just put 6 new Michelin tires on our RV at 5 years. This is the second set that I've purchased (I bought the first set immediately after our purchase of the RV.) Call me crazy but I figured out that it costs me $160 a year more to replace tires at 5 years rather than 7 years and I intend to keep doing it with Michelins. I can share the spreadsheet that I used to arrive at those calculations. I've read the stories about blow outs and am willing to do anything that I can to avoid them. Michelin and Goodyear offered me tires but the Goodyear's profile was wider and I was concerned about more heat build up on the rear tires because of it.
The original tires that I replaced were about 5 years old based on the DOT codes when I replaced them. Our RV's original owner had gotten about 24K miles out of them without incident. Now, I've gotten 5 years out of our first set, also without incident. When I started thinking about:
1. The physical damage to the RV from a blow out
2. The potential safety problems of sitting precariously along a highway somewhere, waiting for help
3. The costs involved in having to buy an emergency tire and have it brought to me
4. The inconvenience of having one of our trips interrupted
I decided that new, brand name tires were, in the long run, the cheapest solution.
Your mileage may vary.
2000 Georgie Boy Landau 36' DP
2005 Saturn Vue toad