[Gamb1t]

I came around to replace my wife's X1 (@58k km) differential oils (haven't done TC yet). What I found was the oil for both front and rear diff were dark and murky. Cannot see bottom.
What concerned me a bit was the low oil. ie the rear diff I managed to extract >550ml and it gulped down ~1l. Some e90 owners noticed this too with their diff oils.

Now I'm thinking did the factory underfill? If I didn't manage to suck the oils out completely which is very possible, it would've overfilled at 50%.

Anyways I replaced with BMW OSP Synthetik 75w90.