Got our 1991 in October and been using a little while fixing things. Tires seemed ok but I am not an expert, didn't check their dates.
Had to boost their pressure from door spec 58 lbs to 65 lbs because the rig is overweight at the back, which can't be reduced. It is what it is for that. Class C thing.
So while up-Island the other day, noticed the outer left rear had a flat and saw a nail in it, so off to a nearby tire store. They refused to fix my flat!
Can't fix it he said, it is over 10 years old and that is against some rule they have. Can you put on my spare then? Nope--it is over 10 years old too, so we won't touch it. ( I wanted to get the work done at the tire store back home I usually deal with)
All my back tires (Es) were 16 years old! The spare is a D, so it is even older, probably from when they put on the Es. (The door specs call for Ds)
So after some thinking about getting one or two or four tires, the only real answer was four new back tires. All because of one nail.
Actually I was lucky to learn all this at a good time near a good tire store. (The front tires are only 5 years old, so they are ok. Still have the old 1991? spare.)
They chose the new tires for me :) Kumho Crugen H51 LT215/85R16E also says 112-115R whatever that means.
I decided it was a good idea to get all new back tires and not just one or two because of being overweight. On scales just before that happened, got:
1630F when GAWR is 1905 so that's Ok, BUT
3930R when GAWR is 3479 Yipes. 451 over (= 992 lbs over)
So I am happy to have all new back tires. I think I lucked out on that episode and not had something happen while speeding down the highway later sometime.