Thanks for the question, Steve!

Yes, Sea Foam Motor Treatment is safe and effective in a 2015 Chevy 5.3. You can use Sea Foam in any type of gas/ethanol blend. Just follow the instructions on the can.

Here’s a little more info on how to use it:

• Sea Foam Motor Treatment in fuel. I recommend you wait until the tank is low (1/4 -1/8 tank), 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.

You could also try High Mileage Motor Treatment. It’s made specifically for stubborn residues and deposits in higher-mileage vehicles. It’s a great cleaner!

Thanks for the question, Robert. Did you put it in the gas tank, or oil crankcase?

In the gas tank, a full 16 oz can is just fine and in fact will work very well to clean the entire fuel system. A high concentration of Sea Foam in gas will work better and faster than a low concentration. I like to add a full 16 oz can to 1/8 tank of gas and run it until almost empty before refueling. Sea Foam Motor Treatment is made with 100% safe petroleum ingredients that can’t harm engine parts or components.

In the oil, do not exceed 1 oz of Sea Foam per quart of oil. If you added 16 oz of Sea Foam to a 5 quart oil system, you’ll want to change the oil.

Thanks for the question, John. Yes, you can use High Mileage in your Harley’s CVO oil. It’s safe and effective and will clean up oil residues and deposits. Just follow the directions on the can. High Mileage is specially formulated to clean stubborn residues, so it’s a good option for older engines.

Hope that helps and let me know if there’s anything else!

Best,

Conner

Sea Foam

Great question, Donald. Yes, Sea Foam Motor Treatment will work in the oil crankcase of a diesel engine. It will clean up oil residues and deposits. Just follow the directions on the can.