So I have to replace one tire on my A4. I have a full size spare that has never been used, and the other 3 tires have 11,000 miles on them. I believe they are all within the 4/32 tread depth limit specified by Audi. Once I replace the flat, I will have 3 tires at 7/32 and 2 tires at 11/32.

Should I:

a) Replace one tire, leaving 3 at 7/32 and 1 at 11/32, and use the other 11/32 as a spare

b) Replace both tires on the same axle with 11/32, use one 7/32 as a spare

c) Replace both tires on one side with 11/32, use one 7/32 as a spare

d) Replace the 2 others (for a total of 4 at 11/32) and have 4 new tires

I'm leaning towards b), since that will potentially stress out only the center diff rather than both center and rear, but according for the spec (4/32), I could do any of the above and be OK. The tires are about $250 a pop, so replacing fewer is better.

Thanks

Link explains why.<ul><li><a href="http://www.tirerack.com/a.jsp?a=AR4&amp;url=%2Ftires%2Ftiretech%2Ftechpage.jsp %3Ftechid%3D52">http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=52</a></li></ul>

You should either replace all 4, or get the new tire shaved to 7/32.

Especially when I'm within the 4/32 Audi themselves recommends for max difference between tread depth. I guess I'll go with 2 new ones on the rear for now, and have them all measured/shaved to match in the near future.

thanks again.