The metal dipstick tube is large and straight enough entering the pan to accomocate a thin wall plastic tube with about 1/4" id. It can be pushed down about 2 1/2" further than the stick ends before it bottoms (I'm assuming to the bottom of the pan). Has anyone done this? Even if all the oil can't be removed, just think of the time and labor cost savings it would mean. The increased frequency of easy and cheap oil changes might offset the lack of "total" removal of old oil. Many boats and other engines with limited bottom access are done this way.