You might want to hold on to that Star Tron.. its definitely not a replacement for Ring Free, and it clearly states in their documentation that it "is not effected by and does not effect any fuel treatment that may already be in use. There is no possibility of chemical reaction"
I bought a couple of bottles to have on hand as I make the transition from last year's MTBE gas to this year's Ethanol. My plan is to run the tank down as low as possible, and fill up with Ethanol fuel w/ Startron to help deal with the transition. I've heard a few scattered reports on Startron working to help prevent Ethanol related problems, and I believe it has been used for several years successfully overseas under a different trade name.
More text from the Startron docs:
"Treating Water in Fuel: As mentioned before water can wind up in your gas or diesel fuel as a result of condensation in the tank. Because water is heavier than fuel, it sinks to the bottom of the tank and forms a distinct water layer. The fuel pick up tube is located at the bottom of the tank so, once this happens, water is supplied to your fuel pump. Obviously the engine can not burn water; soon it starts to stutter and eventually stops running. Additionally, water is corrosive so it deteriorates tank walls and metals in the fuel delivery system. Then enzymes in Startron prevent the water molecules that are in fuel from combining and forming a distinct water layer. Water is reduced to sub-micron size particles that cannot cause corrosion and are safely burned during normal combustion."
Just food for thought..
-- Tom