Thought I'd ask you guys how many miles your getting out of a roll of toilet paper in your Frantz filter before it's full? I'm asking because I've been hearing anywhere from 1000 to 5000 miles. I've been running my unit for 12000 miles and am averaging 3000 miles before the unit is full. Mine is installed on a 2009 Ford 6.4 ltr so soot is a big problem for me. The gas guys are probably able to get far more mileage out of there's before it's a problem. Anyway I'd be interested to hear what your experiences are and what engines they are installed on.