I have used both methods, I always drain or vacuum hot oil. In my cars I drain the oil some times for hours. then pour it off in to the empty oil bottles after I do this I take the drain pan out in to the sun light to see the amount of metal still in the bottom of the pan. If you have ever done this you will realize that a vacuum system would never remove this metal particulates.NorCal_ML320 said:Don't know if anybody saw this article already from cartalk; Tom and Ray discussing using suction type vs. oil drain by gravity.
Does this oil-changing idea suck? - 05/06/2007 - MiamiHerald.com
Not really a disagreement becasue your gravity theory seems OK. I did ask my locak MB shop (3-4yrs ago) how they did the oils in my cars and the said they said they don't use the suction method becasue of the cost of the machine required for this!!!! They drain via gravity!!! That got me thinking: how can my $98 MitiVac beat their very expensive machine??? I think the vacuum type systems do a pretty good job but I wouldn't rely on a simple MitiVac for all my oil changes. MitiVac for A service, dealer for B service.Mike's ML said:TOM AND RAY MAGLIOZZI??? Sounds like a comedy team.
Sorry but I'm going to continue to suck since I have seen previous articles that claim "Sucking" actualy removes More oil and More bottom deposits. I don't know why people think that opening the drain plug sweeps the bottom of the pan clean. The oil drains from directly above the plug opening and not across the bottom of the pan. The oil near the bottom of the pan only drains out under low pressure at the end of the drain cycle where as the suction method, in the case of the dipstick design in the ML, sucks up the deposits from the bottom of the oil pan right from the start of the drain cycle and thus actually gets more of the deposits. And I'm sure many people will disagree and this debate will go on forever.
I did just that. Sucked up all the oil then open the drain plug to see what is left. There were only a few drops left coming out of the drain. So the pump method does a pretty good job in getting all the oil out.ToneMonday said:And NO one seems to be willing to suck it out and then open the drain plug and tell me what runs out - that would settle this stupid argument once and for all. Why is there a drain plug then? Sounds like some folks are afraid to get under their trucks.
This makes sense to me...fkong777 said:IMHO You still should drain the oil at the pan every other or every third oil change.