Can I add a can of Sea Foam to my almost full gas tank and wait to drive it the next day? [SOLVED]

Thanks for the question, Dusty.

Yes, you can add a can of Sea Foam Motor Treatment to a full gas tank and let it sit until the next day. It won’t hurt anything. You can leave it in for as long as you’d like.

If your goal is regular preventative maintenance, adding it to a full tank is perfectly fine.

If your goal is cleaning the fuel system, I’d recommend waiting until the tank is low, about 1/4 tank or less, then adding the full 16 oz can. Drive at least 10–20 miles before refueling. The higher concentration works much better and faster to clean the entire fuel system.