Before filling up with E85, confirm your car is a flex-fuel vehicle (FFV). E85 is not for ordinary gasoline-only cars. If your vehicle is approved for it, compare local fuel cost per mile—not just the pump price—and check whether E85 stations fit your regular routes. E85 can reduce miles per gallon, while performance and emissions effects depend on the vehicle and fuel blend.
1. Confirm your vehicle is approved for E85
E85 is a high-ethanol fuel blend containing 51% to 83% ethanol. The U.S. Environmental Protection Agency says it can be used only in flex-fuel vehicles specifically designed to run on it. A gasoline-only vehicle is not made compatible by adding a small amount of E85 or by using it occasionally.
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Check the owner’s manual and fuel-door label, then verify the vehicle by VIN or through an official vehicle database if necessary. Do this before buying fuel; do not rely on a model’s name or appearance alone.
EPA consumer information on flex-fuel vehicles
2. Plan for lower fuel economy
Ethanol contains less energy per gallon than gasoline. The U.S. Department of Energy’s Alternative Fuels Data Center (AFDC) reports that E85 containing 83% ethanol has about 27% less energy per gallon than gasoline. That is an energy-content comparison, not a promise that every FFV will lose exactly 27% of its miles per gallon.
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E85’s ethanol content varies from 51% to 83%, and the actual fuel-economy change depends on the blend and the vehicle’s calibration. Use your vehicle’s E85 and gasoline fuel-economy ratings as the starting point for a realistic comparison.
3. Compare cost per mile, not just pump prices
A lower price per gallon does not automatically make E85 cheaper to drive on: you may need to buy more fuel to cover the same distance. Compare the cost of each fuel using local prices and your vehicle’s fuel economy on that fuel.
Rank #2
- Treats up to 25 US Gallons of e85, ethanol, methanol or alcohol.
- Special formula encapsulates alcohol, ethanol, or methanol based particles and creates a protective layer preventing them from corroding vital fuel system components.
- Eliminates the corrosive properties in alcohol based racing fuels.
- Helps stop the hygroscopic (absorption of water from the air) nature of alcohol based fuels, reducing or eliminating the amount of water that naturally accumulates in the tanks of alcohol based fuel systems.
- Removes sludge, varnish, and extra hard ethanol carbon deposits in the fuel system; in a single treatment.
Cost per mile = price per gallon ÷ miles per gallon. For example, compare the local E85 price divided by your FFV’s E85 mpg with the local gasoline price divided by its gasoline mpg. The option with the lower result costs less in fuel for each mile under those assumptions. For a location-specific comparison, use the AFDC fuel cost calculator.
4. Check whether E85 is available on your routes
Station access varies by location. The AFDC reports more than 4,200 public E85 stations in 44 states, serving more than 20.9 million FFVs on U.S. roads; these are figures on its current page accessed in 2026. A national station count does not tell you whether a station is convenient for your commute or trips.
Rank #3
- Treats up to 25 US Gallons of e85, ethanol, methanol or alcohol.
- Special formula encapsulates alcohol, ethanol, or methanol based particles and creates a protective layer preventing them from corroding vital fuel system components.
- Eliminates the corrosive properties in alcohol based racing fuels.
- Helps stop the hygroscopic (absorption of water from the air) nature of alcohol based fuels, reducing or eliminating the amount of water that naturally accumulates in the tanks of alcohol based fuel systems.
- Removes sludge, varnish, and extra hard ethanol carbon deposits in the fuel system; in a single treatment.
Search for public E85 stations near home, work and the routes you use regularly, then consider whether the locations and opening hours suit your driving. The AFDC ethanol station locator can help you check coverage.
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Performance and everyday driving
The AFDC says FFVs generally handle similarly on E85 and gasoline, apart from lower miles per gallon. E85’s higher octane can improve acceleration in some FFVs, but that does not mean every vehicle will feel faster or deliver the same benefit.
Rank #4
- Treats up to 25 US Gallons of e85, ethanol, methanol or alcohol.
- Special formula encapsulates alcohol, ethanol, or methanol based particles and creates a protective layer preventing them from corroding vital fuel system components.
- Eliminates the corrosive properties in alcohol based racing fuels.
- Helps stop the hygroscopic (absorption of water from the air) nature of alcohol based fuels, reducing or eliminating the amount of water that naturally accumulates in the tanks of alcohol based fuel systems.
- Removes sludge, varnish, and extra hard ethanol carbon deposits in the fuel system; in a single treatment.
Emissions are not a one-number verdict
E85 is less volatile than gasoline and low-level ethanol blends, and it can offer life-cycle greenhouse-gas benefits. The result depends on factors including the vehicle, calibration, temperature and how the fuel is produced. Acetaldehyde emissions can increase, so “better for the environment” is too broad a claim without specifying the emissions measure and conditions.
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AFDC ethanol emissions information
Do not assume a conversion kit makes a car compatible
Factory-designed FFVs are the straightforward option. The DOE says only a few conversion kits are EPA-certified, and the EPA requires manufacturers to demonstrate emissions compliance. An uncertified conversion can raise legal and warranty problems; verify certification and vehicle-specific requirements with authoritative sources before considering one.
Best Value
- Cleans injectors, valve seats, combustion chambers and other critical fuel components
- Stabilizes fuel and prevents varnish & gum formation in ethanol and gasoline
- Combats deposits and protects your engine oil lubricants from the harmful effects of alcohol combustion
EPA information on aftermarket devices and tampering
Quick Recap
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