David, MV Outer Reef is a 36' trawler with a full sail rig. She is a motor all the time boat. Terry and I just completed a trip on June 14th that started May 2, 2005. We put 1,400 hours on the engine, an SP160 Ford Lehman. Our trip went from Houston, Texas, to Annapolis, Maryland, to Washington, DC, to Abaco, Bahamas, to Key West, Florida, then returned to Port Aransas, Texas. Our engine has a Racor 500 primary filter with a 10 micron element and CAV adapter spin on secondary filters with elements of which I am unsure of the micron level. I was told that they are 4 or 5 micron at the 95% efficeincy level. Thank you for your post. I agree with you and Peter about the 2 vs 10 micron issue. Larry Gregory MV Outer Reef