Seems factory is Fuchs Synthetic, and lots of people like Motul 300 or Liqui Moly.
And lots of people ask about Mobil 1.
Of course all the discussions then break down into arguing over GL4 vs. GL5 in transmissions and the effect on brass syncros, and the question as to which fluids are ok/best for the Diff and center Diff are lost.
So is it ATF (or the proper kind), or Gear Oil (of the proper kind)?
Assuming your car is a slushbox:
Front diff takes gear oil. Automatic section takes ATF. Center diff takes gear oil. Rear diff takes gear oil.
Front, auto, center sections are combined into one unit with three distinct chambers. If you have ATF in your center diff, either someone installed the wrong fluid or you have an internal seal failure.
Growing old is mandatory; growing up is optional.
2005 A6 Sedan Q 3.2 (wife's whip)
2000 A4 Avant Q 2.8 (daily driver)
1980 VW Scirocco (mid-life crisis car)
1983 Mazda RX-7 (revolutionary sports car)
2003 Mini Cooper S (just because)
1995 Mazda Miata, Superdupercharged(anti-Audi)
1999 Mazda Miata SSB (track beotch, no plate)
2003 GMC Yukon Denali XL (the anti-earth)
2004 Dodge Dakota (hey, at least it's stick and 4x4)