different size tires (OD)

["Grant Lenahan" <glenahan@notes.cc.bellcore.com>]

Someone asked why you should not run different diameter (OD)
tires on quattros.

Different ODs means that the front and rear axles turn at different rates
and the differential must take up this difference.  PArticularly on a Torsen,
this means added wear.

Most car companies suggest the same on the two drive wheels
(for 2wd cars) to save wear on the differential between them.

I think that a significant difference could also confuse the
ABS, which senses rotational velocity (rpms) and calculates
a difference to detect a skid. 

re: above:  does anyone know how the ABS adjusts for turning??

Grant