I have a hard time believing they are clean and dry after that long, and if they are then you might have a lucky engine. Dont get me wrong the engines will still run just fine for a very long time. But they won't run AS well for AS long. The main reason we're adding catch cans here is cause we're going for higher HP numbers at which time your gonna end up with more fluid recirculating. It also has to do with how you drive, i floor it pretty much 80% of the time so im gonna be burping alot more oil daily than someone that just drives easy and goes the speed limit