Originally Posted by Mohlman
I had an unrepairable blow out this weekend. The tires i bought last year, and 10k miles ago are discontinued. I've found the same make and size, but the tread is a little different. will this mess up my Diff? or do i need 4 new tires?
I'd look around to see if you can't find the same ones.
What matters to the differential is the ROLLING circumference of tires, when fully weighted on the car. Between different makes of tires, you have no guarantee that the tires will flex the same.
be ok, if you can find the newer variant of the same tire, but even that is potentially pushing your luck. Unfortunately, there's no good indicator of how much is too much variation?
Also, what year/model Subaru? Newer Subaru's (2010+) will be a little more tolerant since they have open differentials in the front and rear.