E85 Dynos & Performance

Installing an eFlexFuel kit and switching to E85 delivers consistent, measurable increases in horsepower and torque—regardless of your engine type. Whether your setup is stock, naturally aspirated, turbocharged, or supercharged, these gains come from E85’s unique chemical properties, not from ECU tuning. Discover the science behind why every build benefits from eFlexFuel + E85, all without modifying your vehicle’s ECU.

At a Glance: E85 Vs. Gasoline Performance

*Effective Octane exceeds 115 due to charge cooling synergies.

Why eFlexFuel + E85 Outperforms Gasoline—For All Builds

1. Knock Resistance: Maximum Timing, Maximum Power

• E85’s high chemical octane (96–100 AKI / 100–105 RON) and superior charge cooling virtually eliminate knock.
• Effective octane exceeds 115 due to synergistic cooling effects.
• Unlike gasoline, which often forces the ECU to retard timing to prevent knock, E85 enables the ECU to maintain optimal ignition advance—even under high cylinder pressures—unlocking full power potential.
• Result: Increased power throughout the RPM range, without ECU tuning.

2. Charge Cooling: Denser, Cooler Intake Charge

• Ethanol absorbs 2.4× more heat than gasoline during vaporization (841 kJ/kg vs. 350 kJ/kg).
• Intake air temperatures can drop by 15–30°F (8–16°C), increasing air density by 4–7%.
• Cooler, denser air delivers more oxygen per cylinder, supporting stronger and more consistent power—especially under load or repeated acceleration.
• Result: Smoother, more responsive power delivery across all throttle positions.

3. Faster Flame Propagation: Harder, Quicker Power Strokes

• Ethanol burns faster than gasoline—4.2 m/s flame speed vs. 3.5 m/s—resulting in quicker ignition and faster flame travel.
• 12% faster pressure rise in the cylinder improves combustion efficiency.
• 5% shorter combustion duration maximizes energy extraction from each cycle.
• Result: Sharper, more efficient power strokes that translate into more usable torque and horsepower with improved throttle response.

4. Oxygen Content: Cleaner, More Complete Combustion

• E85 contains ~30% oxygen by weight, compared to gasoline’s 0–3.5%.
• This high oxygen content allows for more complete combustion, increasing power output and reducing emissions.
• Result: Enhanced performance under all combustion conditions.

**Actual IAT reduction depends on sensor location and engine configuration. Most IAT sensors measure air before fuel injection, so the full cooling effect of E85 may not be reflected in readings. The true benefit occurs in the intake manifold and combustion chamber during vaporization.

How eFlexFuel Kits Make It Happen—No Tuning, No ECU Changes

• eFlexFuel kits do not modify your ECU or adjust timing/boost. They simply deliver the correct fuel quantity for any ethanol blend, allowing your engine to fully utilize E85’s properties while preserving OEM safety and emissions systems.
• Dyno-proven gains: All performance improvements are achieved using factory timing and boost—no tuning, no remapping, just optimized fueling.
• Seamless operation: Whether you fill up with E85, gasoline, or any blend, eFlexFuel adapts instantly to deliver consistent performance and drivability.

Summing It Up: eFlexFuel + E85 Performance Gains vs. Gasoline

eFlexFuel kits enable your engine to harness E85’s superior octane, oxygen content, charge cooling, and combustion speed—resulting in more power and torque across the entire RPM range, without requiring ECU modifications.

• Whether stock or modified, naturally aspirated or boosted, you’ll see gains throughout the powerband—not just at peak.
• Knock resistance allows your ECU to maintain advanced timing, maximizing safe power output.
• eFlexFuel delivers these benefits automatically, with full factory reliability and safety.

Understanding Dyno Results

What Are Peak Gains vs. Max Gains—and Which Matters More?

We reference both Peak Gains and Max Gains (also known as Curve Gains) in our dyno comparisons. Each measures performance improvement, but in different ways:

Peak Gain refers to the difference in horsepower at the highest point of each dyno run—the maximum HP recorded.

Max Gain / Curve Gain represents the largest horsepower increase observed at any point in the RPM range. This typically occurs under the curve, which is why it’s often called “curve gain.”

Max Gains better reflect real-world performance improvements—what you feel during acceleration and driving—because they occur within the usable powerband. Peak gains, while impressive, are often brief and occur near redline.