Fuel Management

[stuffinbox]

Greetings,
I'm sure the subject has been over discussed in the past but some of you can surely clear this up. I get a wide range of answers to my question about fuel tank level and the effect from condensation and bio contamination over time. I have two tanks and currently keep one as empty as possible, full enough that I won't pull air into the system, and the other with fuel that I estimate will last for near term use say for coastal sailing for the next 4-6 months. When the time comes to add more I put the fresh fuel in the tank that had the minimum and switch tanks. I am running fuel purchased for highway use because it has the highest turnover rate and in my way of thinking is coming out of storage tanks that turn over faster. Some people say they keep the tanks on their boats topped off to minimize condensation and add biocide to offset gel contamination. Whitch approch works the best, full treated storage or consumption and replacement with fresh fuel? I monitor my water seperator and filters regularly and so far have had no problem but I would like to know if this is going to catch up with me over time and cause problems.
Thanks again
Tom and Sandy
S/V Tara

You'll find lots of opinions on this, and very few people who actually have hard DATA. You have two seperate issues. One is length of time for storage (longer is worse) and a partly empty tank is bad too. Obviously you can't improve both of these at the same time!

In the abcense of hard information about what to do, your best bet, is to keep your fuel filters in good shape, draim any water from the tanks as often as possible, and periodically (annually?) have a commercial fuel polisher come by and give the whole tank a good cleaning. If you do this you'll have no problem.