The most powerful, accurate and capable app for determining octane and ethanol content of arbitrary fuel mixtures

This calculator provides accurate blending and filling instructions for any gasoline and any ethanol blend to arrive at a desired octane or ethanol percentage. Why bother calculating an ethanol percentage of your fuel blend when you really need to know the octane! The App accommodates any existing fuel blend at any state of fill and provides needed fuel volumes to reach a desired octane or ethanol percentage goal at a desired fill level. Get the precise octane you need for your engine (or perhaps for your particular tune) which will provide the power and safety you demand. The App will even down blend mixtures, allowing you to reduce octane or ethanol to a desired level.