Tobin,

I have a hard time understanding why this is even vaguely controversial. I use the Topsider type devices, and have for probably a dozen years now. I started when MB began enclosing the bottom end of the engine compartment with plastic parts held in place with cheesy fasteners. I rounded the drain plug hex corners off and broke the plastic cover fasteners on my 1991 350SD the first time I tried, and became convinced MB, who serviced the car for the previous owner, never touched these items in the 4 years and 70,000 miles the previous owner had the car. I also rounded the flats on the bolt on my 1986 190E the first time I changed oil - and I took ownership after the first 1,000 mile service. I was very pleased with the option to use the dipstick tube and avoid these extra, irritating steps. .

My regularity of oil changes increased significantly, especially in the Winter. I do not have a garage and for many years did not have a paved driveway. In the Winter there is nothing particularly macho or traditional about lying in an icy, slushy mess while you change the oil. The Topsider method makes this much less of an obstacle to doing the job with serious regularity.

With the Topsider I estimate I remove 98% or more of the used oil in the engine that can be practically removed by either method. 98% or more of what remains is only 5,000 or 6,000 miles "old" (I use Delvac 1). The whole operation is over in 45 minutes. This includes a 15 minute ride to heat the oil up first, changing the oil filter, the little O-rings on the filter housing cap stem, and fully cleaning up the mess - including pouring the old oil into the empty new gallon containers the Delvac 1 comes in. There is no excuse when it gets that easy to change oil regularly even in the Winter in my situation.

I think once the oil is changed regularly, and hot, the few dribbles of old oil left, if it is more than the remnants left using the pan drain plug overnight, are absolutely negligible. It is much more important to change the oil regularly.

As others have noted there is also nothing wrong with using the drain plug. It may even get a few more of the last molecules that will come out, out. But if you drive another week or two because of rain, snow or some other reason for not wanting to crawl under the car, any theoretical benefit is lost.

So, don't take this as preaching the Topsider is better. It likely is not better. But a Topsider is pretty effective and clearly good enough. My 1998 E300D TurboDiesel will run with fresh Delvac 1 in it, for several hundred miles before it turns black. If a lot of old oil was in the system that would not be the case.

I am also not a real fan of getting my hands in used Diesel engine lubricating oil, as it is pretty nasty getting it off and I do not work on the car's engine with gloves (my mistake in many cases). With the Topsider I can do the job with nearly no mess. I use a technique I learned from someone on this site to get the oil filter out without touching it. I pull a plastic bag backwards over the hand I reach in to get the oil filter out, and once I get my finger on the little handle on the filter (through the bag), I pull the filter up and then roll the bag down over the filter as it emerges from the filter housing. I lose a drip or two and wipe them up with a paper towel.

One more benefit of Delvac 1 is that it wipes off pretty cleanly and when you do get it on your hands it is much easier to wash off than anything I have tried before, including many years of Mobil 1 15W-50.

So the point is the Topsider method meets MB's requirement for oil removal when changing the oil. I have used it for more than a decade and find it very convenient. The decision to use it or not is about as meaningful as which side of your head you part your hair, even if you are bald. It is a personal preference and I see no downside to selecting the device from the perspective the engine's long term happiness, while I find the clean up much more reliable - no spills or other disasters. Good luck, Jim

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Own:
1986 Euro 190E 2.3-16 (291,000 miles),
1998 E300D TurboDiesel, 231,000 miles -purchased with 45,000,
1988 300E 5-speed 252,000 miles,
1983 240D 4-speed, purchased w/136,000, now with 222,000 miles.
2009 ML320CDI Bluetec, 89,000 miles

Owned:
1971 220D (250,000 miles plus, sold to father-in-law),
1975 240D (245,000 miles - died of body rot),
1991 350SD (176,560 miles, weakest Benz I have owned),
1999 C230 Sport (45,400 miles),
1982 240D (321,000 miles, put to sleep)