Surprisingly high 100c cSt with a 1.27 FD.. maybe the 0w40 helped you out some there but couldn't save your TBN @1.2..you might consider looking for a lube with a higher starting BN or consider shorter oci's.
Where'd all the Ca come from?
Last edited by Mad_Hatter; 09/12/1901:10 PM.
Re: Mobil 1 ESP 5w-30 on AUDI Q5 2015 2,0 TFSI 15000 km
While you technically still have some reserve alkalinity, the TBN is IMO low enough to be concerned about corrosion. I'm surprised your 100c kv is at 12+. Seems you either thickened up or the 40 grade bumped you up???