E85 / E15 Fuel Finder

Locate ethanol fuel stations near you and calculate blend ratios for performance driving.

25 mi

Allow location access or search by city/zip to find E85 stations near you.

Blend Mix Calculator

Enter how much E85 and pump gas you are mixing to see the resulting ethanol content and octane.

Total Volume 15.0 gal
Ethanol Content E30
Ethanol Percentage 30.0%
Estimated Octane ~97

Target Blend Calculator

Enter your target ethanol percentage and tank size to see how much E85 and pump gas you need.

E85 Needed 5.0 gal
Pump Gas Needed 10.0 gal
Estimated Octane ~97

Quick Reference: E85 + 93 Octane Mixes (10 gal tank)

E85 93 Oct Ethanol % Blend Name Est. Octane
1 gal9 gal16%E16~94
2 gal8 gal22%E22~95
3 gal7 gal28%E28~97
4 gal6 gal34%E34~98
5 gal5 gal40%E40~99
6 gal4 gal46%E46~101
7 gal3 gal52%E52~102
8 gal2 gal58%E58~103
9 gal1 gal64%E64~104
10 gal0 gal70%E70~105

* Assumes E85 at 70% ethanol content and pump gas at 10% ethanol (E10). Octane values are estimates.

Important Notes for Performance Drivers

  • E85 ethanol content varies by season (51-83%). Use an ethanol content tester for precision -- do not assume 70% without verifying.
  • Higher ethanol requires more fuel due to lower energy density. Expect roughly 3-5% more fuel consumption per 10% increase in ethanol content.
  • Ensure your vehicle is tuned for your target ethanol blend. Running high ethanol on a stock tune can cause dangerously lean air/fuel ratios.
  • Flex-fuel vehicles (FFVs) can safely run any blend from E0 to E85. Non-flex vehicles must have a proper ECU calibration from a qualified tuner.
  • Ethanol is more corrosive than gasoline. Verify that your fuel system components (lines, injectors, fuel pump, seals) are ethanol-compatible before running high blends.

Frequently Asked Questions

E85 is a fuel blend containing 51-83% ethanol mixed with gasoline. The exact ethanol percentage varies by season and region. In summer, E85 typically contains around 70-83% ethanol, while winter blends may drop to 51-70% to help with cold starting. E85 is sold at specially labeled pumps at participating gas stations and is generally cheaper per gallon than regular gasoline, though it contains about 27% less energy per gallon.
Only flex-fuel vehicles (FFVs) can safely run pure E85 without modifications. FFVs have ethanol sensors and engine calibrations that automatically adjust for any ethanol blend from E0 to E85. Non-flex-fuel vehicles can potentially run lower ethanol blends (such as E15-E30) with a proper ECU tune from a qualified tuner. Running high ethanol content on a stock tune in a non-flex vehicle risks dangerously lean air/fuel ratios, misfires, and potential engine damage. Always consult a professional tuner before increasing your ethanol content.
E85 has an effective octane rating of approximately 100-105, depending on the actual ethanol content in the blend. This high octane rating is one of the main reasons performance enthusiasts use E85 -- it allows for more aggressive ignition timing and higher boost pressures on turbocharged engines without risking detonation (knock). Even partial E85 blends, such as E30 or E40, significantly raise the octane rating above what premium pump gas offers.
E85 itself does not inherently produce more power, but its high octane rating (100-105) and charge-cooling effect allow engines to be tuned more aggressively. With a proper ethanol tune, turbocharged vehicles commonly see 5-15% power gains compared to a 93 octane tune, thanks to more ignition advance and the ability to run higher boost safely. Naturally aspirated engines typically see smaller gains of 2-5%. The trade-off is that E85 has about 27% less energy per gallon than gasoline, so fuel consumption increases by roughly 25-30%.
The only reliable way to know the exact ethanol content is to use an ethanol content tester (also called a fuel composition sensor). These devices cost around $30-100 and measure the ethanol percentage directly from a small fuel sample. The pump label "E85" only guarantees the fuel contains between 51-83% ethanol per ASTM D5798 specifications. Many performance drivers test every fill-up and log the results, since ethanol content directly affects their tune's air/fuel ratio targets. Some stations display the current ethanol percentage on the pump, but this is not universal and may not always be current.