How long can an already opened bottle of Sea Foam last before it “expires”? I poured some ounces in the crankcase for my upcoming oil change, but there’s a lot left over before I pour it in again for the next oil change, but that won’t be for awhile obviously so I don’t want to use “expired” Sea Foam. I don’t want to pour it in the gas tank as I only want to use Sea Foam in my crankcase.
Good question, Casey. If the cap is on tight, it will last a long time (many years). It’ll last just fine until your next couple oil changes.