1997 A6 Quattro Wagon

[Richard Hoffman]

> > Is it  true that one must change all four tires on this type
> > of car if one tire goes bad?
> > I've never heard that before and was wondering if it's
> > just particular to that vehicle, or is it that way with all
> > the all-wheel drive cars?
>
> Sorta. Kinda. No.
>
> You can't run tires that are different sizes as they can stress the drive
> train or throw off the traction control or ABS systems. However, the
> difference in diameter between a new tire  and a worn tire will be less
than
> 1/10", which is not relevant.

I would disagree!  After an accident in my parents A6 (not my fault,
everyone ok) one tire needed to be replaced.  Unfortunately, we couldn't get
the same brand tire and the others had approx 30k on them.  The alignment
was reset but the car wouldn't track correctly, no matter how many times we
had the alignment rechecked.
Replaced all 4 tires with tires of the same make and treadwear, no change in
alignment, car tracked perfectly e3very since!
Richard