Mobil 1 kill lifters. More at 11

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

>>Is it advisable to use synthetic oil in this Audi?  I have a '90 80q =
>>that I switched over to Mobil 1 at 60K miles and it caused my lifters to =
>>go bad.  After replacing all of the lifters and switching back to "real" =
>>oil and changing at 3K intervals, I haven't had another problem.

Highly unlikely.
Did Mobil buy you new ones?

While we all have our preferences, it really does not matter
either Mobil1 or regular oil are fine in your new car or your
older car, regardless of what someone told you.

I use Mobil1 in my I-5 Audis.

Grant