there's no way to really tell. I think the specs back in the day was like every 50k miles. I've pulled GM fuel filters out (the metal cannister ones on under the rig on the frame) that weighed like they were full of lead, which i always assumed it meant it was fuel of debris.
I've looked inside more fuel tanks in my career than I could count, and 99% of the time, the inside of the fuel tank is spotless, not one spec of debris. I think that's why they stopped putting fuel filters on gas engine rigs. The only times i really see debris in gas tanks is old cars that have sat for years, and we were restoring them. Always seemed like any corvette that sits for more than a year will rust bad enough in the tank to have to replace the tank and sending unit. Nowdays, most all tanks are plastic, so rust isn't a concern.
Diesel fuel tanks are another matter, I've seen all kinds of debris in those tanks. I believe this debris usually comes from people filling their tanks from their tanks on the farm or construction sites.
I've looked inside more fuel tanks in my career than I could count, and 99% of the time, the inside of the fuel tank is spotless, not one spec of debris. I think that's why they stopped putting fuel filters on gas engine rigs. The only times i really see debris in gas tanks is old cars that have sat for years, and we were restoring them. Always seemed like any corvette that sits for more than a year will rust bad enough in the tank to have to replace the tank and sending unit. Nowdays, most all tanks are plastic, so rust isn't a concern.
Diesel fuel tanks are another matter, I've seen all kinds of debris in those tanks. I believe this debris usually comes from people filling their tanks from their tanks on the farm or construction sites.
