I guess the M103 engine in my '88 300E with 170K miles is an oddball then. It uses NO oil between 3,300 mile changes. It doesn't go down on the stick at all. In fact when an engine shows absolutely no oil usage it makes me wonder if the top rings are oiling as they should.
I bought the car with eighty something thousand miles and complete records including every receipt. There was a receipt from an independent shop showing they put valvestem seals in. The same shop had some very questionable expensive repairs on the car, so I doubted whether they really did the work. But, since visiting this forum I have read where valve stem seals are a common repair on these engines. It must be a very worthwhile thing to do.
'84 Euro 240D, 516K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in