Time to replace tires, tread not issue, age is

[DaveFL]

This winter I was planning to put two new tires on front and rotate, front to inside rear. Took off rear wheels to do brake check and lubrication and found original tire that looked good in place has separation. Thread is 10 compared to new of 11 on my gauge. Now my best move would be to replace all 6 keeping one for spare.
All rears were 1998 and front were 2004, Michelins 8 years versus web forums 5 makes sense.

[Phoenix]

Can't tell; is that a Michelin XPS Rib? Please provide model, load range and size. Thanks...

[DaveFL]

Michelin Piolot XZA original equipment, but the 04 are XRV and has brown on the sidewall so it is breaking down too, just surprised to have two bubbles thru the name, like ribs. 225/70 19.5 for MH not trailer.

[Robfike]

We went with the Goodyear G670RV tires. Screw the french. The Goodyears don't age anything like the Michelin's. Ours are 5 years old with NO age degradation showing anywhere.
Rob

[DaveFL]

Bubble tire was 12 yrs old, but very little thread wear.
My new tires will be Continental, Made in USA and only 2/3 price of Michelin at Tire Depot. I can save 700-1000 compared to best local price, by having them shipped to door and then taking them to be mounted and balanced.

[Lumatic]

Originally Posted by DaveFL

Bubble tire was 12 yrs old, but very little thread wear.

The majority position seems to be any trailer time over 5 years old is living on borrowed time regardless of the mileage or tread wear. Another good idea is to check the manufacturing date on new tires so you are not buying tires that have been sitting in some warehouse for a couple of years.