All Gumout products are compatible with standard OEM fuel tank components. However, specialty aftermarket or racing components should be tested by the manufacturer. In general if the component is compatible with pump gasoline, it will be compatible with gasoline treated with Gumout®.
If E85 is run in the vehicle the Gumout® product to use is Multi-System Tune-Up. It is designed to be soluble in the high alcohol content of E85. Most other gasoline additives (including Gumout®) are not completely soluble in E85 and may separate from the fuel.
For E0-E10 run any of the Gumout® products. For E85 use Gumout® Multi-System Tune-Up.