E85 Blend Calculator
Mix exactly to your target ethanol content directly at the pump based on your remaining fuel.
True E85 is usually 70-85%
Standard 91/93 is usually 10%
Ethanol Blend Compatibility
Not all vehicles are compatible with high ethanol blends. Verify your vehicle's fuel system compatibility before using E85 or E10 blends.
- Ethanol is hygroscopic (absorbs moisture)
- May degrade fuel system components in older vehicles
- Always confirm with manufacturer specifications
Methodology
Final Blend: Volume-weighted average of ethanol content
Formula: (Ethanol Volume × Ethanol %) + (Base Fuel Volume × Base Ethanol %)
Frequently Asked Questions
Can I blend fuel types mid-race?
Not recommended. Different fuels have different burn characteristics, octane ratings, and oxygen content. Blend before a session starts for consistent tuning.
Is ethanol blending accurate for E85 performance?
This calculates volume ratios, but E85 oxygen content (35%) affects combustion significantly. Always dyno test after major blend changes to validate power.
What's the efficiency loss with ethanol?
E85 typically requires 20-30% more fuel to produce same power (lower energy density). However, the octane boost often enables more ignition advance = net power gain.
Disclaimer & Legal Notice
All tools and calculators provided by Lapsite are for informational and educational purposes only. While we strive for mathematical precision, these results are approximations and should not be used as the sole basis for critical engineering, financial, or safety decisions. Lapsite Ltd and its creators provide no warranty, express or implied, regarding the accuracy or fitness of these calculations for any specific use.Always double-check calculations independently, especially for safety-critical components such as brakes, suspension, or structural changes. By using these tools, you agree that Lapsite Ltd is not liable for any mechanical failure, financial loss, or injury resulting from the use of this data.
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