David Rive
Senior Member
How long is diesel good for? The boat I bought in August has tanks (300 gal) that are 3/4 full. That fuel is on average probably 3 to 4 years old, based on what the previous owner has told me. Should I get rid of it?
Should I get rid of it?
I have had more problems with adding biocides to tanks over the years versus just filtering the heck out of the fuel. The biocides kill the growth that then just falls to the bottom of the tank. Then rough weather stirs it all up clogging filters all over again. Constant, high volume filtering is the answer. The preventative measure would be to add biocide BEFORE the growth of the bacteria (a long period of disuse). But who has the foresight to do that!? We ALL want to use the boat as much as possible. To own a boat and not use it for years signals the end of ownership usually.
I too have been "donated" old diesel fuel from folks that consider it "too old" to use. I mix it with new, maybe 50/50, then use it in my machines. Never had a problem. Some was over ten years old.
When you buy fuel at the dock, do you know how long it's been in the storage tanks for? Middle of the season it may be fresh but early season, who knows?