thebigfish

My owners manual specifies 0w-40 or 5w-40. Mobil 1 being the only non-Mercedes brand approved. My mechanic (who reads service bulletins and forums like you or I might read Steinbeck or Grisham) says that the more important issue (than wt.or brand) is the formula specs of the oil which is printed on the label. He claims owners manual should give the formula spec numbers for use in MBZ GL550. Anyone know about this? This is my first post. : )

KrustyKustom

Oil specs are indeed more important than the weight. I have a GL350 and I have to use MB 229.51 or the new MB229.52 spec oils which are available in several weights. There are other brands that will meet your spec, while Mobil1 is probably the most trusted.

thebigfish

THanks for the confirmation. Is the approved oil formulation #s listed in the owner's manual and are they printed somewhere on oil containers? THanks. Steve

Fourdiesel

The MB number should be on the container if it is approved for that number.