04 3.0i diff oil
hi guys, just wanted to see if anyone has put anything other than the bmw oem oil in their diffs. i hear the 04 and up x5's can run Redline 75w-90
question is, is it safe? my dealer is telling me they only sell their oem gear oil in 5L jugs ($200) which is a little off the board.
redline or royal purple? what do you guys think