My take on the Air-Sep is that it is a very expensive device designed to move a large amount of cash from your pocket to Walker Air-Sep's. It does work, and will save you a few cents in oil and will keep a few drops of oil off the road and your driveway (so will a 25 cent plastic bottle mounted at the end of the blow by tube). If you need to run your engine in a sterile environment, it may be worth the big bucks.