E85 Scout Is Now on the iPhone

E85 Scout started as a web app because that was the fastest way to get it into drivers' hands. Now it's a real iPhone app too: E85 Scout is on the App Store, free.

If you haven't used E85 Scout before, here's the short version. It maps more than 5,000 E85 stations across the US. For each one it shows the ethanol content drivers actually measured there, not just what the pump label says. "E85" can legally be anywhere from 51% to 83% ethanol depending on the season and the supplier. If your car is tuned for E85, that gap matters.

What the iPhone App Does

Find E85 near you

• A map of more than 5,000 E85 stations, centered on where you are
• Search by station name, address, city, state, or ZIP
• Filter by minimum ethanol %, how recent the last test is, blend (E15 to E85), or verified stations only
• One tap to open a station in Apple Maps, Google Maps, or Waze
• Save favorites and sort them by distance, ethanol %, or most recent test

Know what's in the tank

• Each station's most recent verified ethanol reading, with color-coded freshness so you can tell a test from yesterday from one from last spring
• Separate readings for each blend a station sells (E15, E20, E30, E40, E50, E85)
• Verified stations are marked, and so are private or fleet-only pumps you can't actually use

Built for the pump

• Ethanol % calculator: enter your tank size, fuel level, current blend, and target blend. It tells you how many gallons of E85 and pump gas to add, with an octane and AFR estimate.
• Quick Verify: no test kit? Confirm a station is still open and selling E85 while you're there, so the next driver doesn't waste a trip.
• Report a station that's closed, private, or listed wrong, or submit one we're missing.
• My Contributions shows what happened to everything you sent in, and why.
• Light and dark mode, following your phone's setting.

How to Test E85 and Log It From Your iPhone

The data is only as good as the tests behind it, and every reading in E85 Scout comes from a driver who checked. Logging one takes about a minute:

1. Pull a sample at the pump with an ethanol tester. Most work the same way: water to the fill line, fuel to the next line, cap, shake, and let it settle.
2. Read the line where the layers separate against the tester's scale. That's your ethanol percentage.
3. Open the station in E85 Scout and add a test. Enter your reading and take a photo of the tester.
4. The photo gets checked. A vision model reads the tester in your photo and compares it with the number you typed. If they match, your test is published. If the photo is unclear, a person reviews it.

That photo check is why the numbers can be trusted: a typo or a made-up number doesn't land on the map unchecked. It's also why the app needs an account. Every reading is tied to the person who submitted it, and submissions are rate-limited.

Already Using the Web App?

Sign in on the iPhone with the same email and password. Your favorites and the tests you've submitted belong to your account, so they're already there. The web app at app.e85scout.com isn't going anywhere. It's still the way to use E85 Scout on Android or a computer.

Privacy, Briefly

Your location is read on your phone to center the map, show distances, and confirm you're at a station for Quick Verify. Your coordinates aren't sent to our servers. A test or Quick Verify does record which station it was for. Test photos are published as the evidence behind a reading. You can delete your account and its data from inside the app at any time. The full details are in the privacy policy.

What's Next

An Android app is on the way. Also on the roadmap: planning E85 stops along a route, crowd-sourced E85 prices, and alerts when a favorite station gets a new test. Got an idea? Tell us on Featurebase. That's where most of what's in the app came from.

And if E85 Scout saves you a wasted trip, a rating on the App Store helps other E85 drivers find it.

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