Also important to note, Subaru’s AWD system is picky as hell and a tread depth difference across the axle is actually pretty likely to damage your diffs or transmission.
Meaning, if you need to replace a tire, you replace all four tires or else run the risk of catastrophic damage to the vehicle. The AWD works great and it’s a good system but it can and will screw you out of a thousand bucks worth of tires with no warning. Pros and cons.
(Sorry for the comment on a 2 week old post)
For those in the US, Tire Rack can shave down a new tire to a specific depth for you. You just need to measure the other tire(s) to give them a measurement.
Had to do this for my Subi once and it worked like a charm. No mechanical problems after (although I did sell the car, like, a year later).
