Do I really have to wait until the gas tank only has 2 gallons left in the tank before adding Sea Foam? [SOLVED]

Thanks for the question!

You don’t have to wait until your tank is that low, but it’s the most effective way to get a strong cleaning concentration. When there are only a couple gallons of fuel in the tank, adding a full can of Sea Foam creates a higher ratio of treatment to fuel, so it will clean faster and better than if you were to add a can to a larger volume of fuel.

That said, you can add Sea Foam to a full tank at any time—it will still work to clean and lubricate, just at a lower concentration. Many people add a full can to a full tank as part of regular  preventative maintenance.

So the short answer: use it whenever it’s convenient, but adding it when the tank is low gives the strongest cleaning results.