Doesn't a filter spend a good part of its life in bi-pass? What happens when an engine is stone cold pushing 60-80 psi of oil pressure? How about 45 psi cruising at 70 on the highway? Is the oil getting filtered at all? We had this discussion at work a few days ago and a mechanic posed that question and left a few of us scratching our heads. I don't think the filter plays as important a role as most people think.