How much Sea Foam in a 2003 Ford Expedition XLT 5.4? [SOLVED]

Thanks for the question, Don. Here’s what I’d do:

• wait until you have a low tank (1/8 to 1/4 tank or so)
• add a full 16 oz can of Sea Foam Motor Treatment. High Mileage would work great as well.
• drive at least 20 miles
• refill with fresh fuel

The high concentration of Sea Foam does a great job cleaning. Adding it to a low tank will make it work much better and quicker than if you add it to a full tank. It’s the best way to make the most out of a can. Hope that helps!