I'm going to take my Cummins turbo-diesel powered trawler on the Great
Loop next summer, meaning I will be in some warm places where things
might grow in my tanks. I also read all sorts of ads indicating I need
stuff in my fuel to clean injectors, increase cetane, clean carbon,
reduce wear, increase mileage, etc.

Is any of this true? What do I really need to add to my fuel?

Capt. Jeff