Thanks for the question, David, and congrats on the RV!

To clean up the fuel system, your goal will be to create a relatively high cleaning concentration of Sea Foam to fuel. Wait until you have a low tank of fuel (1/4 tank or less), and add 3-6 oz of Sea Foam per gallon of fuel (three 16 oz cans would be a good cleaning concentration; you can also get 20 oz Truck & SUV size cans that would work great too). Drive at least 20 miles before refueling with fresh fuel (or as long as you are comfortable with on a low tank). That gives the treated fuel time to work through the system and clean.

Thanks for the question, David. Use Marine PRO. It will clean and lubricate the entire fuel system, as well as prevent gum and varnish from forming in fuel. Works great in marine applications.

Here’s how I’d recommend using it depending on what your goals are:

• For routine, everyday maintenance: add 1 ounce of Sea Foam per gallon of fuel. It does come in 1-gallon jugs that you can get at NAPA or other auto parts stores (you might have to have them order it, but I looked up a NAPA in your area and it said they could ship to store for pickup the same day). Adding Marine PRO to every tank of fuel is best practice for keeping a fuel system clean and preventing common fuel-related problems
• For periodic high-concentration cleaning, wait until you have a low tank of fuel (1/4 tank or so), add a high concentration of Marine PRO (at least 2-4 oz of Marine PRO per gallon of fuel), and use up as much of the treated fuel as you’re comfortable with before refueling.

Hi Jack,

Thanks for the question! Yes, you can use Sea Foam Motor Treatment in your vehicle. It’s compatible with your 2016 GMC Yukon. Just follow the instructions on the can.

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

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.

Great question, Jessica, and you’re on the right track.

I’d use Sea Foam High Mileage. 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, including on injectors.

Hi Dennis,

Thanks for the question!

Best practice would be to drain the fuel.

After one year though, it should still start and run fine. If you don’t drain it, I’d wait until you have 2-4 gallons, add an entire can of Marine PRO, and run it for at least 20 minutes (just don’t run out of fuel). The high concentration will do a good job cleaning up any gum and varnish that formed while the fuel sat. After that, add 1 ounce of Marine PRO per gallon to every tank of fuel. That will prevent gum and varnish from forming going forward.