Original post by: rehm70 ,
My father had the original Fuel Preporator on his 1985 BCIII Cummins. It ate seals in the pump, and made zero difference in performance or fuel economy. I have a FASS on my 2001 12.7 DDECIV. I also installed new liness. Like my father, I have seen zero difference in performance or economy. I do believe the filters do a better job of filtering than a standard system, otherwise I would sell it. Im cautiously waiting for something to fail on it, since it is in constant salt spray.