No. An ethanol content sensor is not required for the tune to operate as intended.

However, many customers choose to install one as a convenient way to monitor ethanol content. Two available options are:

• Innovate MTX-D Complete Gauge Kit: Uses a physical gauge to display ethanol content and fuel temperature. The kit includes the gauge, ethanol sensor, and required wiring harnesses.

• Nostrum ESSIM Ultimate DIY Package: Uses an iOS or Android mobile app rather than a physical gauge. It can monitor ethanol content, fuel pressure, and fuel temperature, and includes the components needed for ethanol-content and fuel-pressure monitoring.

Generally, no.
Once a Tune Request has been submitted, the fuel type of your tune cannot be changed.
However, you can purchase an Additional Tune to cover a different fuel type.

The ideal fuel type depends on your driving goals, local fuel availability, budget, and willingness to manage fuel quality.

For customers seeking maximum flexibility, Auto-Octane allows operation across a wider range of fuel grades. Customers seeking maximum performance from pump gas often prefer a dedicated 91+ or 93-octane calibration. Ethanol-based calibrations such as E50 and E85 typically provide the highest performance potential but require ethanol availability and proper fuel management.

Because ethanol content varies by station, season, and region, E50 should never be mixed using assumptions alone.

The recommended approach is to test the ethanol content of your E85 and pump gas, then use the ZFG Ethanol Calculator or E50 Cheat Sheet to determine the correct blend ratio.

Proper blending improves consistency, drivability, and performance.

We offer multiple fuel types, tuning goals, and tuning options. All tunes are custom and will be written for the fuel type, tuning goal, vehicle, and vehicle configuration specified at purchase:

Fuel Type
Fuel availability varies by region, so we generally recommend selecting a tune based on the highest-quality fuel consistently available in your area.
• Auto-Octane (87-93 • Octane + up to E30)
• 91+ Octane (91-93 Octane + up to E30)
• 93 Octane (93 Octane + up to E30)
• E50 (40-60% ethanol content)
• E85 (70-90% ethanol content)

Tuning Goal
This is the starting point for your calibration and tells us what you're looking for in terms of responsiveness, gains, and end-goals:
• Daily Driver (stock-like yet refined)
• Performance (Goldilocks - not too much or too little)
• Race (maximum power and full optimization)
• Tow (towing and high work-demand applications)

Depending on the vehicle platform, you may also have the option of either a Standard Tune or DMS™ (Drive Mode Specific) Calibration, which allows different tuning characteristics to be assigned to the factory drive modes.

Auto-Octane is a fuel type we offer for tunes. Auto-Octane tunes are designed to accommodate a broader range of pump-gas fuel octanes than a dedicated premium-fuel tune, such as 91+ Octane or 93 Octane.

While Auto-Octane provides excellent flexibility, dedicated premium-fuel calibrations generally offer greater performance potential.

Auto-Octane is often a good choice for customers who travel frequently or live in areas where premium fuel availability varies. This fuel type is also well-suited for use as a tow and travel tune.

Fuel quality and available octane ratings can vary significantly throughout Alaska.

We generally recommend using the highest-quality fuel consistently available in your area and selecting a tune designed for that fuel.

When discussing tuning options, please let us know the fuel grades available locally so we can provide the most appropriate recommendation for your specific situation.

We do not recommend running a lower-octane fuel than your tune is written for.

However, occasional use of 91 octane on a 93-octane tune is generally acceptable.

Performance and consistency may be reduced compared to using the intended fuel grade. If 91 octane is the highest-quality fuel regularly available in your area, a dedicated 91-octane is recommended.

To ensure your vehicle performs as intended, it’s important to consistently run the specific fuel type your tune was designed for. The fuel type is noted in the file name of your tune.

For all pump gas tunes, we do NOT recommend ethanol-free fuel, regardless of octane rating. We recommend running fuel with at least 10% ethanol content.

Using lower-octane or inconsistent fuel can impact performance, drivability, and overall reliability.