Additives that you put in every tank of fuel is a waste of money. That comes to you from a professional tech.
That said, I have used Sea Foam in a lot of carbon ed up engines, both in the oil and fuel. Even in the trans. It works...... but you don't need it in every tank.
Marvel Mystery Oil is good stuff for similar issues, but it does seem to do a better job of freeing stuck piston rings.
Star TRon seems to have great marketing. Fooling people into thinking that they need to have it in every tank.
I add nothing to my 10% blend fuel. I don't drain tanks in the winter, or shut off the tank, or drain the carbs. My stuff starts every time I need it. I do on occasion dump the gas out of my 2 strole engines and put fresh in, but that has more to do with evaporaton of the fuel leaving too much oil, and the fact that I get tired of pulling a rope....
