We have just had a flat tire due to a nail, and it probably cannot be repaired. I have read that there is a very high sensitivity to exactly matching tires on the XC in order to avoid serious damage to the AWD system, and that this requires replacing all four tires in the event that one of them must be replaced. In our case, the current tires have a tread depth of 8/32nds, while a matching new tire will have a depth of 10/32nds. Is it likely that this difference of 2/32nds in tread depth would be enough to cause concern about the AWD system? If one tire would be questionable, would mounting two new tires (both at front, or both at rear) be a better choice, or should we just scrap everything and buy all four new?

Thanks for any insight you folks can provide.
--
Mike Sullivan ('91 745 (171k), '93 965 (147k), '95 855T (60k), '98 V70XC (78k). Past Volvo's: '85 744 (256k), '86 245 (165k), '86 245 (195k), '88 745 (208k).

The Volvo technical service bulletin that covers this is posted
on this thread:

http://www.brickboard.com/AWD/?id=597610

It recommends you replace all four and if you can't do that 2 new ones
must go on the front. (Which leads me to wonder how you would then
rotate the tires?)

That certainly seems like the definitive answer. Thanks for the help
--
Mike Sullivan ('91 745 (171k), '93 965 (147k), '95 855T (60k), '98 V70XC (78k). Past Volvo's: '85 744 (256k), '86 245 (165k), '86 245 (195k), '88 745 (208k).