Can You Mix Gasoline and E85? A Comprehensive Guide
Yes, you can mix gasoline and E85, but doing so safely and effectively depends on several factors, primarily your vehicle’s compatibility with ethanol-blended fuels. Mixing the two fuel types haphazardly without understanding the implications can lead to performance issues and potentially damage your engine.
Understanding E85 and Gasoline
Before delving into the specifics of mixing, it’s crucial to understand the characteristics of each fuel type.
What is Gasoline?
Gasoline is a petroleum-derived fuel primarily composed of hydrocarbons. It’s designed for optimal combustion in internal combustion engines, providing energy to power vehicles. Different grades of gasoline exist (e.g., regular, mid-grade, premium) based on their octane rating, which indicates their resistance to knocking or pre-ignition.
What is E85?
E85, short for 85% ethanol, is a blend of 85% ethanol and 15% gasoline. Ethanol is an alcohol produced primarily from corn or other plant-based sources. It’s often touted as a renewable fuel source and can offer certain performance advantages, such as increased octane. However, E85 contains significantly less energy per gallon than gasoline.
The Impact of Mixing Gasoline and E85
Mixing gasoline and E85 results in a fuel blend with an intermediate ethanol content. The effects of this mixture depend heavily on the following:
- Vehicle Compatibility: The most crucial factor.
- Existing Fuel Composition: The ratio of gasoline and E85 already in the tank.
- Desired Performance Characteristics: Fuel efficiency versus power.
Compatibility is Key: Is Your Vehicle Flex Fuel?
The single most important question is: Is your vehicle designed to run on E85 (is it a “Flex Fuel” vehicle)? Flex Fuel vehicles (FFVs) are equipped with sensors and engine management systems that can detect the ethanol content of the fuel and adjust the engine parameters accordingly. They have fuel system components engineered to withstand the corrosive effects of higher ethanol concentrations.
If your vehicle is not a Flex Fuel vehicle, using E85, even in a diluted blend, can cause significant problems:
- Fuel System Damage: Ethanol can corrode rubber and plastic components not designed to withstand it, leading to leaks and fuel system failures.
- Engine Damage: Lean running conditions (too much air, not enough fuel) can occur, leading to overheating and potential engine damage.
- Performance Issues: Stalling, rough idling, and reduced fuel economy are common symptoms.
Best Practices for Mixing (If Allowed)
If your vehicle is a Flex Fuel vehicle, mixing gasoline and E85 is generally safe. However, understanding best practices is still important:
- Avoid Overfilling with E85: Even in an FFV, consistently running with nearly pure E85 may not be optimal. Sticking to blends between E10 (10% ethanol) and E50 (50% ethanol) often provides the best balance of performance and fuel economy.
- Monitor Performance: Pay attention to how your vehicle runs after mixing. Note any changes in fuel economy, acceleration, or starting.
- Consult Your Owner’s Manual: Your owner’s manual is the definitive guide for fuel recommendations for your vehicle.
FAQs: Mixing Gasoline and E85
Here are some frequently asked questions regarding the mixing of gasoline and E85, designed to provide further clarity on this topic:
FAQ 1: What happens if I accidentally put E85 in a non-Flex Fuel car?
If you accidentally put E85 in a non-Flex Fuel car, immediately stop driving the vehicle. Drain the fuel tank and replace it with the correct gasoline type recommended by the manufacturer. Continuing to drive could cause significant damage to the fuel system and engine. Contact a mechanic if you’re unsure how to proceed.
FAQ 2: Will mixing E85 with gasoline increase my car’s horsepower?
In a Flex Fuel vehicle, mixing E85 with gasoline can potentially increase horsepower. E85 has a higher octane rating than gasoline. The vehicle’s engine management system can take advantage of this higher octane to advance ignition timing, resulting in more power. However, the increase is often modest and may not be noticeable.
FAQ 3: Does E85 improve fuel economy compared to gasoline?
Generally, E85 decreases fuel economy compared to gasoline. Ethanol contains less energy per gallon than gasoline. Therefore, you’ll typically get fewer miles per gallon when running on E85 or high-ethanol blends.
FAQ 4: Can I mix different octane levels of gasoline with E85?
Yes, you can mix different octane levels of gasoline with E85 in a Flex Fuel vehicle. The engine management system will adjust to the resulting fuel blend. However, using the recommended octane level of gasoline as a base is generally advised for optimal performance and engine longevity.
FAQ 5: Is there a specific ratio of gasoline to E85 that’s “ideal”?
There’s no universally “ideal” ratio. It depends on your specific Flex Fuel vehicle, driving conditions, and performance goals. Many users find that a blend around E30 to E50 offers a good balance of performance and fuel economy. Experiment to see what works best for you.
FAQ 6: Will using E85 void my car’s warranty?
Using E85 in a non-Flex Fuel vehicle will likely void your warranty, as it constitutes using the vehicle outside of its intended operating parameters. However, using E85 in a Flex Fuel vehicle as intended generally will not void the warranty. Consult your warranty documentation for specific details.
FAQ 7: Can mixing gasoline and E85 cause starting problems in cold weather?
Yes, high ethanol concentrations can cause starting problems in cold weather. Ethanol doesn’t vaporize as readily as gasoline, making cold starts more difficult. Flex Fuel vehicles typically have cold-start systems to compensate for this, but using a higher gasoline content blend in cold climates can still improve starting performance.
FAQ 8: How do I know if my car is Flex Fuel?
Check your owner’s manual. There’s also usually a yellow gas cap or a sticker on the fuel filler door indicating that the vehicle is Flex Fuel. Furthermore, look for the “Flex Fuel” badge on the vehicle itself.
FAQ 9: Can I store E85 for long periods?
E85 is more susceptible to water absorption than gasoline. This can lead to fuel degradation and phase separation (where the ethanol separates from the gasoline). Avoid storing E85 for extended periods (more than a few months), especially in humid environments. Add a fuel stabilizer if long-term storage is necessary.
FAQ 10: Does E85 have any environmental benefits?
E85, when produced from sustainable sources, can offer environmental benefits compared to gasoline. Ethanol is a renewable fuel, and its combustion can result in lower greenhouse gas emissions, depending on the production process. However, the environmental benefits are a complex and debated topic.
FAQ 11: Can I use E85 in my lawnmower, motorcycle, or other small engine?
Generally, no. Most lawnmowers, motorcycles, and other small engines are not designed to run on E85 or high-ethanol blends. Using E85 in these engines can cause fuel system damage and performance problems. Always use the fuel type recommended by the manufacturer.
FAQ 12: Where can I find E85?
E85 is available at many gas stations, particularly in areas with strong corn production or government incentives for renewable fuels. Use online fuel finder tools and apps to locate E85 stations in your area.