Thanks for the question, Richard! Yes, you can use Sea Foam in your Packard. It’s made with petroleum ingredients that won’t harm anything and work well to clean fuel residues and varnish.

Here are a few recommendations on how to use it:

• Sea Foam Motor Treatment in fuel. I like to wait until the tank is low (2-4 gallons), 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.
• Sea Foam Motor Treatment in oil. Add 1 ounce 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, and it allows all the reliquefied oil residues to be drained away with the old oil.

If it’s sitting for any length of time, you can add Sea Foam to every tank to prevent the fuel from degrading and gum and varnish from forming while it’s in storage.

Thanks for the question, Tara! No, it does not matter how long it takes to make it those 200 miles. The important part is you get at least 100 miles in so the Sea Foam has time to circulate and clean while the oil is circulating.

Yes, you can add Sea Foam to your external oil reservoir. Add 1 ounce of Sea Foam per quart of oil. Either Sea Foam Motor Treatment or Marine PRO would work great in the oil.

Thanks for the question!

Yes, you can use Sea Foam Motor Treatment in the fuel tank and oil of a Mercedes diesel. Just follow the directions on the can.

Note that Sea Foam is NOT for use in a DEF system. Do not add it to the DEF tank.

Good question, John. It’s safe to leave Sea Foam in the oil for as long as you’d like. That said, 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. Add 1 oz of Sea Foam per quart of oil in the crankcase. Do not exceed this ratio.