My wife had a tire go flat and drove on it, so it's destroyed. Tires are Goodyear Assurance Triple Tread 205/65-15HR's, we've put 15k on them in the last year, and who knows how many miles are on them total.

On sale at Tirerack right now for $88ea plus a $40 cash-back deal or something, which is fantastic. They're normally over $100ea.

But, do I buy 2, so that they will be the same diameter on one end of the car, or do I need all friggin' 4?

Or....is it already game over because she drove with a flat tire?

<a href="http://forums.audiworld.com/a6100/msgs/73814.phtml">Click here</a>

Basically, the front &amp; back and side-to-side need to be close in rolling circumference. Mine are off slightly front to back (8/32 tread front vs. 11/32 back) with no ill effects. Side-to-side they're the same. The idea is that the Torsen and differentials shouldn't be churning all the time.

I don't think running on the flat for a short time will hurt anything. Quattro is much too robust for that.

I had the same problem but I found a pair on ebay with the same approximate tread depth.

I'm not big on used tires anyway, unless they've been marked for which direction they were running.