Can I just put E85 in my flex fuel car?
Yes, but only if your car is a true flex-fuel vehicle (FFV). FFVs are designed to run on gasoline, E85 (up to 85% ethanol), or any blend in between; non-FFVs should not use E85. This guide explains how to verify your vehicle and what to expect at the pump.
Understanding E85 and flex-fuel vehicles
E85 is a high-ethanol gasoline blend that typically contains up to 85% ethanol and 15% gasoline. Ethanol has a higher octane rating but lower energy content than pure gasoline, which often leads to lower miles per gallon. Flex-fuel vehicles are specifically engineered to handle ethanol blends and automatically adjust the engine’s fuel mix and timing to accommodate different ethanol levels.
What makes a car an FFV?
Factory flex-fuel vehicles are certified to run on gasoline, E85, or any blend up to 85% ethanol. They typically carry FFV labeling on the exterior and have fuel-system components and engine software calibrated for ethanol use.
Can my car use E85?
To determine if your vehicle can use E85, check the owner's manual, look for FFV badges, and inspect the fuel door or under-hood labels. If you’re unsure, contact the manufacturer or a dealer.
Ways to confirm your vehicle's capability:
- Check the owner’s manual for fuel compatibility notes.
- Look for a “Flex Fuel” badge on the back of the car or a sticker at the fuel door listing gasoline/E85.
- Check the vehicle’s VIN or the manufacturer’s website for FFV certification.
- Ask a dealer or service professional if you’re uncertain.
Bottom line: If your car is not an FFV, do not use E85. If it is FFV, you may use E85 up to 85% ethanol, keeping in mind other considerations below.
What to expect when using E85 in an FFV
Using E85 in a certified FFV triggers the vehicle’s engine-management system to adjust fuel and air mixtures. This can affect performance, fuel economy, and cold-weather behavior, but the engine is designed to tolerate ethanol blends when it’s within the approved range.
Key considerations:
- MPG and fuel economy: Expect a noticeable drop in miles per gallon due to ethanol’s lower energy content per gallon.
- Performance and responsiveness: In many cases, you may not notice a dramatic change, though throttle response can vary with blend and temperature.
- Fuel price and cost per mile: E85 is often cheaper per gallon, but the lower energy content means you may spend about the same per mile as with gasoline, depending on prices at the pump.
- Cold-weather behavior: Ethanol can affect starting and drivability in very cold conditions, though FFVs are designed to handle these blends.
- Maintenance and warranty: If you use E85 as recommended for an FFV, there’s generally no warranty issue. Using E85 in a non-FFV or using unapproved blends can cause damage and may void warranties.
Conclusion: For FFV owners, using E85 is supported and common, but be prepared for lower mpg and potential seasonal performance differences.
Practical steps for fueling with E85
Follow these steps to ensure you’re using the right blend and fueling safely at the pump.
- Confirm your car is an FFV and that E85 is an approved fuel blend for your model year.
- Find a station that clearly offers E85 (look for signs that say “E85” or “Flex Fuel”).
- Verify the pump is dispensing E85 and not a different ethanol blend (some stations offer E10, E15, or E85).
- Fill up as you normally would, avoiding topping off after the nozzle automatically shuts off.
- Drive normally and monitor your fuel economy over several tanks to gauge the impact of the blend on your specific vehicle.
In practice, confirm FFV status first, then choose E85 at a compatible station, and monitor performance and economy over time to determine what works best for your driving patterns.
Summary
If your vehicle is a verified flex-fuel vehicle, you can safely use E85 (up to 85% ethanol). Expect lower mpg and variable performance depending on temperature and blend, but your engine management system will adjust accordingly. Always verify FFV status via the owner's manual or manufacturer resources before fueling with E85, and be mindful of fuel availability and price in your area.
