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.

Thanks for the question! Add 1 oz of Sea Foam per quart of oil in the crankcase.

We recommend adding it 100-300 miles before your next oil change. That gives the Sea Foam enough time to circulate and clean. It also lets you drain away all the reliquefied crud (residues and deposits) when you change your oil.

Good question! Yes, Sea Foam is safe and effective in a Cummins X15 diesel. Just follow the directions on the can. You can also check out our page on diesel maintenance basics that has a few recommendations for using Sea Foam in diesel engines.

https://seafoamworks.com/diesel-engine-maintenance-basics/

Thanks for the question!

Add one ounce of Sea Foam per quart of oil in the crankcase.

Also, check out the article on our site about oil burning and its common causes. That will help explain what Sea Foam can and can’t do for a vehicle that’s using oil.

https://seafoamworks.com/how-to-fix-oil-burning/

If the oil use is caused by varnish or buildup, Sea Foam can help. Sea Foam reliquefies oil residues and deposits so they can be drained away with the old oil. I’d recommend the High Mileage version. It’s a great cleaner.

We recommend adding it 100-300 miles before your next oil change. That gives the Sea Foam enough time to circulate and clean. It also lets you drain away all the reliquefied crud (residues and deposits) when you change your oil.

Thanks for the question, Chris! You can leave Sea Foam in your oil until your next regularly scheduled oil change. It’s safe to leave it in there for as long as you’d like.

That said, we recommend adding it 100-300 miles before an oil change. That gives it a chance to circulate and clean while allowing all the reliquefied residues to drain away with the old oil when you change it.