Originally Posted by
seibaatgung
Never thought of the magnet trick!
It's possible that there are other wear/breakdown particles that are not attracted to magnets; brass, copper or bronze (the "yellow" metals), but these would be less abrasive. In any case, I only use the recycled oil for the "flush"... the final fill is always fresh oil.
I've been meaning to put some drained, unfiltered oil under a microscope and compare it to the magnetically-filtered oil. If I do this, I will try to get images and post them.