Originally Posted by oldskewel

My 2001 3.0i's owner's manual calls for, "Approved oils are in SAE classes 5W-40 and 5W-30"



I use Castrol Edge 5W-30 in my X5.



I use Mobil 1 European Formula 0W-40 in my Porsche Cayenne. Am aware of how Mobil 1 changed the product without changing the name. I don't think Porsche has changed their recommendation away from that (that is the original factory specified oil on that car).



I actually would not worry about any of the factors mentioned so far here (exact brand, LL spec, exact weight). If the oil is sludgy, there is something wrong well beyond these factors.



If the car is newly owned, could it be that previous owners did not maintain it well, and now the frequent detergent oil changes are setting free all the ancient deposits?