Okay, let's say that on the 112 engine, this is the case. It could very well be that because of obstructions between the suction location and the drain plug location, you get more with the PROFESSIONAL, expensive system found in the dealers.
I do have a question about sucking and then pulling the drain plug. How long did you have the plug out after sucking? It would take a while for that small quantity of oil that is left to move around and find its way out.
If this is the case on the older cars I would be shocked.
Secondly, you said this, but some may not notice that the topsider will not necessarily do this.
Yes, I am still a skeptic. My brother in law who is my tech at the dealership has offered to drain my oil with the plug if I wish. I don't have any problem with them using their contraption because I will do an oil and filter change between theirs anyway.
I have no problem with the dealers doing things to increase shop efficiency, or even with the factory designing cars with this in mind. In fact I doubt that many other car companies give a hoot whether their dealers can have an efficient shop.
My contention is that the pan should be laid out so that I can pull the plug and drain ALL the oil out. For the person that maintains their own car after the warranty period, I want to be able to remove ALL the oil to prevent more frequent oil changes.
I am a stickler about my oil drains because I want MAXIMUM engine life and when I do take that engine apart I want it to be COMPLETELY SLUDGE FREE.
I have already pointed a finger at myself and said in effect "LARRY IS ANALLY RETENTIVE REGARDING OIL CHANGES." I can understand shop efficiency, I can't understand not putting a pan underneath and draining the oil into the pan instead of spending money on a contraption that some say cannot be used to remove the oil while it is hot and has contaminants thoroughly mixed.
So, as I've said before, call me what you want (and some here have already started with that) and do what YOU want to do. I will continue to put a pan under a hot engine, pull the plug and let it drain overnight.
Yes, I will have some gunk under my fingernails, but the inside of my engine will remain clean.
One last thing. There is one good thing about the topsiders. It has people changing their oil that might not otherwise do so. That's definitely a good thing. It allows those who detest crud under their fingernails to change their oil, with some degree of success, without relying on someone else to do so.
Have a great day,
Change oil hot and change oil often,