Tires OEM Audi or OEM Subaru

Nope, you don't need to change all four. I had a similar problem on my Subaru Legacy years ago, and I simply bought one new tire and then took it to a local race shop and had them shave the new tire to the same depths of the old one.

It's an '09 2.5 Special Edition auto. Likes: Fairly \"sporty\" feeling. Lots of features for what it's costing me. decent stereo. Cons: weak engine. drivers seat doesn't go back far enough. armrest is awful. fuel economy sucks for a car this size. crappy stock tires.

My car on 15x8's is sporting 195/50 15's and the tires are slightly stretched-- not too stretched in my opinion but just help to round out the sidewall a bit