Stop Guessing. Start Knowing Your Exact Ethanol Content.
Running E85 on your 2021+ Mazda 3 2.5L Turbo? Ethanol content at the E85 pump can vary from E50 to E85 or higher depending on season and station. Regular premium gas can have up to 10% ethanol at some stations. No more calculating gallons at the pump and guessing ethanol percentage. Just open the app and know.
Key Features
• Real-time ethanol content monitoring via Bluetooth
• Displays exact ethanol percentage (E-content) in the Fuel-It! or JB4 app
• 0–5V analog output for JB4 or flash tuning integration
• Genuine Continental ethanol sensor for OEM-grade accuracy
• Plug and play fuel line integration
• Ethanol safe PTFE fuel lines and fittings
• Installs in approximately 30 minutes
• No cutting or permanent modification required
Why You Need an Ethanol Sensor on Your Mazda 3
E85 pumps rarely dispense true E85. Seasonal blends can drop into the E50 range without notice. If you’re tuning for ethanol, this matters.
With this kit you can
• Dial in your exact E85 blend every fill-up
• Avoid running too much ethanol on a pump gas map
• Maximize timing and boost safely on ethanol maps
• Maintain consistent performance at the track
• Protect your engine from unknown fuel mixtures
The Bottom Line
If you’re running E85 on your turbocharged Mazda 3, a flex fuel sensor isn’t optional, it’s essential.
Power, consistency, and safety all start with knowing exactly what’s in your tank.
Download the Fuel-It! ECA app here:
Vehicle Fitment
• 2021+ Mazda 3 SKYACTIV® 2.5L Turbo
* For the Mazda JB4 platform connect the white wire to position #4 on the JB4 25 pin harness. Select WMI Ethanol Setup option 0 to enable pin location 2/3/4 flex fuel input.

