Interesting in that the old timer that worked on the powerboat motor said to use SeaFoam. It had been sitting for at least 2 years. Then the old timer at Advance Auto who has helped me through many boat engine issues, especially with the BMW in the Catalina, also told me to use SeaFoam as an additive in the diesel fuel when we lay up for the winter. For what it's worth, I did add a can to a full tank of fuel last fall and it seems fine.

Now, all that said, the crew down at our club buys $35 a pint additive for their diesel that is supposed to reduce algae growth ect and so forth. Then they add a stabilzer.