Since I'm a relative newbie, I may have missed this topic in the past. I thought of this idea during my first few visits to BITOG ... and the 3,000 mile oil change thread reminded me of it. It may be a bad idea or pointless. Is there some contraption that would pump your old oil through something like a bypass filter to remove minute particles not caught by the oil filter? ... to sort of "refresh" the oil by removing the debris. The filtered oil could then be reused with maybe just additives put back in the oil. Obviously the filtering mechanism should not introduce more particles and should be done in a "sterile" environment. Or it could be as simple as letting gravity do the work. Put the old oil in a container and let it move through a filter into another container. From my [limited] reading, it appears oil itself can last much longer than the 3000 mile interval, but at some point in an extended OCI the insolubles and particles can get kinda high. Would this be a way to use the oil for a long while, and just periodically clean it out for further use? It might provide the benefit some advocate with the 3000 mile oil change (get the bad stuff out), but also the environmental and monetary benefit many look for with the extended OCI. Any thoughts?