Mercedes designed all their engines made after the early '70 for vacuum oil extraction. They are designed so that the dipstick tube can be used as a suction tube and will remove as much oil as removing the drain plug will remove! Every few years somebody challanges that and will actually extract the oil and then remove the drain plug to see how much more comes out. If they've not been careless, NO MORE OIL will come out (well maybe a few drops, but usually not even that). I have been using suction (a Big Boy Topsider) to change my oil for almost 7 years and it works fine. I would slightly prefer a powered suction device as it could extract the oil a little faster (it takes about 10-12 minutes to extract the up to 8 qt that's in my 603.96 engine - but I use the time to change the filter and check the tires and check/top up fluids).

Marshall