Should I have a full tank when I add Sea Foam to my gas tank? [SOLVED]

Thanks for the question, Alan. To get the most cleaning power out of a can of Sea Foam, I like to wait until the tank is low (1/4 -1/8 tank), add the whole 16 oz can, and then drive for at least 10-20 miles before refueling. It’s safe to add a high concentration like that and it works very well for cleaning fuel residues and deposits. Add it to fuel like this every 3,000 miles or once a year.

Hope that helps and let me know if you have any questions!