In April 1991 Mercedes sent out TSB 00/86a

It reduced the recommended MAX oil fill amount of ALL 601/602/603 engines sold in the US by 0.5 liter. This revised level is about 25% below the MAX mark on the dipstick!

Then in 1995 they sent out TSB 00/57A. In it, they cautioned that owners should NOT top up the oil frequently. They point out that there should NEVER be sufficient oil in the engine so the level ever reached above the MAX or FULL mark EVER. They point out that the optimal level is midway between the top and bottom marks, and that there is NO advantage to adding oil before it reaches the ADD or MIN mark and owner "...should refrain from frequently "topping off" the engine oil level."

I have owned/driven 22 different Mercedes cars for more than a total of a million miles and EVERY one (gas or diesel) would exhibit increased to excessive oil consumption if driven at highway speeds with the oil at or near the MAX level. Drop the oil content of the engine to a level about midway bewteen MAX and MIN and the oil consumption would usually be reduced a lot.

If you happen to use full synthetic oil (especially Mobil synthetics) the oil level registered on the dip stick will under report the oil content of the engine from anywhere from a pt to a qt unless the engine has been shut down and the oil allowed to drain back into the pan - for HOURS. With the Mobil syhthetics that I use, this takes between 6-8 hours! If you top up a recently shut down engine with Mobil 1 15W50 oil to the MAX mark, the engine will be overfilled by at least a qt and oil consumption will be high! I suggest that you check the oil in the AM before starting the car the first time that day. On OM60x engines (and late OM617.95 engines made after 4/84) the distance between the two marks is 2 liters (2.15 qt). If the level is above the MIN mark add a qt. When checking the engine on the road, if the level is below the MIN mark add no more than ONE qt. That's plenty as long as it brings the level up to the MIN mark. Check it the next day after it sits overnight and see where it is. It will usually indicate engine oil content between a pint and a quart above where it was before fully draining. If you engines behave like mine, there will be PLENTY of oil in the engine. I've been trying for several years to estimate what the actual oil content would be when the dip stick reading was MIN or midway at say 5 minutes, or 15 minutes or a couple of hours after shutdown, but the results are NOT consistant. This measuring issue is NOT a serious problem with conventional oils or with MANY/MOST so called "synthetic" oils that have a high hydrocracked oil content.

Marshall