It takes 30 min of idle time to get 1 ounce of fuel to your engine. It is best to add fuel to your tanks add the stabil and then run wot one last time in your favorite waterway. I also use stabil in every fillup. And even though a lot of people disagree with each other to leave the gas or drain it. I believe leaving the tanks full prevents most moisture buildup in tanks. That's just my opinion. People do both with no complications so to each their own I suppose.