How much Sea Foam Motor Treatment should I put in my gas tank for my 2011 Scion xB? [SOLVED]

Thanks for the question, Alejandra. For regular preventative maintenance, add 1 ounce per gallon of fuel. For periodic cleaning, add at least 2 oz of Sea Foam per gallon of fuel. In fact, the more you add to fuel, the better and quicker it works.

Here’s what I’d do in your Scion:

Wait until you’ve got a low tank of fuel (1/8 or less). Then add a full can of Sea Foam, and drive until almost empty before refueling (at least 20 miles). That will do a great job cleaning up the fuel system and critical engine areas. We recommend adding it every 3,000 miles or so to keep things running clean.