E30 Fuel Calculator
Figure out how much ethanol and 93 octane to add to hit your target blend.
Version 6 · Oct 28, 2026
1. What's in your tank?
ZFG-supported Fords & Lincolns plus other common E30 cars. Tank sizes are published specs. Double-check your owner's manual.
Gauges and apps hide a reserve below 0%, so a tank never takes its full rated capacity. Calibrate this once from a real fill for exact amounts.
Calibrate from a fill
2. Fuel at the pumps
E85 sold at the pump can actually be E51–E83 depending on season and supplier. Enter a measured value rather than assuming 85%.
3. Add fuel in this order
Adding ethanol first is convenient, but it does not guarantee a precise blend. Tank gauge readings, residual fuel, pump concentration, and fill volume introduce error. Use a verified ethanol sensor or test to confirm the actual blend before high-load driving.
4. After you pump
Type in what the pumps actually showed. If the 93 stops short, that's fine: stop at the first click. The page works out your real blend and sets it as your starting blend for next time.
Saved fill-ups
Saved only in this browser on this device. Clearing website data or using private browsing can erase the history.
| Date | Before | E-fuel | 93 | Final |
|---|
Important
Confirm with your tuner that your 93-octane calibration supports your chosen ethanol concentration, and follow any logging or fuel-system guidance. This is a blending estimate, not a measurement of actual ethanol content or an approval to run E30. Never exceed the limit for your calibration.
Disclaimer: This calculator is provided "as is," for informational purposes only, with no warranty of any kind. Results are estimates and may be inaccurate. You are solely responsible for what you put in your vehicle. aDude LLC is not liable for any damage to your vehicle, engine, or fuel system, or for any other loss, injury, or expense resulting from use of this calculator or its results. By using this page you accept these terms.