If a 245/40/19 series tire is put on a 9.5" wide rim, will it be okay to take it off and put it onto an 8.5" wide rim? I'm not too sure if tires stretch permanently after being on a wider rim for too long.

If it's possible to switch tires like that on staggered rims, does it need to be done every tire rotation (5000km) or just every other rotation (10000km) will be fine?

EDIT: Now that I think about it, if the tire size is the same, will the rear wheel even look wider?

Thanks!

JP