Should I drain the old gas before putting Sea Foam in a truck that’s been sitting for 6 years? [SOLVED]

Thanks for the question.

With 6 year old fuel, I would go ahead and drain it before adding Sea Foam. Here’s an excerpt from our page on starting a car that’s been sitting for a long while:

Gummy varnish and deposits are a common cause of problems like rough idle, loss of power, or poor fuel efficiency in a car that’s been sitting. Adding a high concentration of Sea Foam Motor Treatment or Sea Foam High Mileage to the fuel tank is an easy way to clean fuel residues and deposits from the entire fuel system. If your engine has been sitting for a long time, here are three steps to get it cleaned up and running well again with Sea Foam:

• Start by draining or syphoning the old fuel from the tank.
• Add 2-3 gallons of fresh fuel and a can of Sea Foam High Mileage to the fuel tank. If you can’t drain all the fuel, you’ll still want to add some fresh fuel to bring back fuel volatility.
• Drive until almost empty (at least twenty miles if possible) before refueling with fresh fuel.

You can read the full article here: https://seafoamworks.com/starting-a-car-thats-been-sitting/

Let me know if you have any questions – happy to help!