Hey Stephen,

Good question! Sea Foam Motor Treatment will keep fuel fresh for up to two years. More specifically, it will preserve ignition vapors and prevent fuel gum and varnish from forming.

Note: Sea Foam won’t “restore” old fuel. Add it to fresh fuel before storage.

Good question, Dan.

It’s safe to add a lot of Marine PRO to your boat’s gas tank. In fact, a high concentration of Marine PRO in fuel does a great job cleaning up fuel residues and deposits that often cause performance problems like rough idle, hard starts, and loss of power.

Here’s what I’d do: Wait until you have a low tank of fuel (1-2 gallons). Then, add a full can of Marine PRO to the fuel. Run your boat at least 20 minutes if you can (just don’t run out of gas!), and don’t be afraid to run it hard. After that, refill your fuel tank as normal and add 1 ounce of Marine PRO per gallon of fuel. That will prevent fuel from degrading and preserve ignition vapors.

In oil, add 1 ounce of Marine PRO per quart of oil.

Good question. Sea Foam Motor Treatment will stabilize stored fuel up to 2 years. Sea Foam will help preserve ignition vapors and prevent fuel from degrading.

Here are a few things to keep in mind:

• It’s best to add Sea Foam to fresh fuel (rather than fuel that’s already been in a gas can for a while).
• Sea Foam can’t “restore” old fuel.
• Add at least 1 oz of Sea Foam per gallon of fuel that you’re storing.

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

Thanks for the question, Kris. First off, there is nothing to worry about. Marine PRO is completely safe for a diesel engine. It’s not labeled for diesel engine use because the product was formulated for gas engines and the claims haven’t been tested in a diesel. That said, Marine PRO will still work to clean critical engine areas in your diesel. Go ahead and run it as normal.

In the future, you might be interested in Sea Foam Motor Treatment in the gallon container. You can find that at most auto parts stores.

Good question, Mike. Yes, you can just pour it in the gas tank. If there’s still old fuel in there, go ahead and drain as much of it as you can. You’ll want to use a high concentration of Sea Foam in fresh fuel. That will work great to clean up any fuel residues or deposits from the bad fuel that was in it before.

Here’s what I’d do: add 4 oz of Sea Foam and 8 oz of fresh fuel. Then, run it normally until it’s out of fuel.

If you’d like, you can add 1 ounce of Sea Foam per gallon of fuel to every tank after that as preventative maintenance. The Sea Foam will prevent the fuel from degrading as well as prevent fuel gum and varnish from forming (which is the most common cause of engine trouble in small engines).

You can add it to oil as well. It will reliquefy any heavier oil residues that have formed so they can be drained away with the old oil. Add 1 ounce of Sea Foam per quart of oil. Run it for 15-20 minutes before changing the oil.