[JimD]

I do not drain for 3 hours and leaving a little behind is the most logical explanation of my observations. I checked the oil level on the way home yesterday, after driving about 25 miles and it read at maximum. So tilted towards the passengers side by 1.5 inches did not measurably change things.

I change at 5K mile intervals so I am not at all worried about not getting it all out. I am also not worried that I do not have enough in. I am at about 92.5K miles and the engine is not using any oil as far as I can tell, between oil changes.