E85 blend calculator

1. Look at the fuel gauge needle in your car.
2. Tap the matching mark on the gauge below — it works just like your dashboard, from Empty to Full.
3. Enter your tank size and target octane (or leave the defaults if you're not sure).
4. Read the two numbers under "Add E85" and "Add 91 octane" — that's how much of each to pump.
5. Optional: open "Advanced" to fine-tune octane ratings, how much fuel is left at Empty, or switch between gallons and liters.

Add this to your Home Screen (iPhone):
Tap the Share icon in Safari (square with an arrow) → scroll down and tap "Add to Home Screen" → tap "Add." It'll show up as its own icon and open full-screen, just like an app.