- Apr 20, 2016
I have a small sailboat with a Universal 5411 that uses only about 1/4 tank per summer. I fill the tank and treat it with fuel stabilizer each winter but I'm mixing new fuel with old fuel and I have no idea how old the old stuff is. Can I just keep treating it indefinitely or should I pump out the old stuff and replace with fresh fuel? I'm not having any problems yet. I refill it every Fall only because I read somewhere that the tank should be full before it's laid up for the winter to prevent condensation in the tank otherwise I would just burn down what's in the tank.