[s-cars] What's the list wisdom on tire depth.. tolerance for 4 tires.

[Brett Dikeman]

On Tue, Aug 18, 2009 at 12:20 PM, jeff
postupack<jeff.postupack at gmail.com> wrote:

> Classic question.. with 3 tires at about 65% remaining tread (nope I didn't
> measure the tread depth yet)
>
> and buying one new Conti.. what is the List wisdom concerning how close to
> match tread depth on a Quattro?

There are two concerns- first being the obvious rolling diameter
differences causing differential wear, but keep in mind, lots of us
aren't perfect at rotating our tires and differential failure is
virtually unheard of (though with one tire, you're going to be loading
up two differentials, not just the center.)  Less obviously would be
different behavior from the tire leading to unexpected/inconsistent
handling.  Tread depth matters, but age of the tire matters too.

The cheapest option would be to shave the new tire down to the same
tread depth which will at least mean relatively similar grip in the
rain/snow and same rolling diameter, but the difference in age of the
rubber will still cause different levels of grip.  However, if you're
not planning on tracking the car and don't hoon the car on the street,
you'll probably never know or notice.  For maximum safety under
braking, the new tire should be in the back.

-B