I use an extractor. 8.5 out.............8.5 in. I'm not concerned with any residual. Definitly not a half a pint left in mine. even if it were, you have more dirty residual in the engine components already, and it is very minor amount as well. Change it often enough and the "residual" oil still has a long life left in it as well. I know we are all picky on here but any small out left, if indeed it is left, isn't a problem. I know people like to drain from the bottom due to desire to possilby get anything sitting inthe bottom of the pan out with the drain event, but I think you can do that every other change or less without concern. I change my oil once a year and it usually only has about 3k miles on each change so that's in my comfort level as well. To each his own, what ever makes them comfortable. I absolutely love my extractor.