What is E85?

What is E85? A Comprehensive Guide

E85 is a high-octane fuel blend that contains 85% ethanol and 15% gasoline. Ethanol is a renewable fuel made from corn and other plant materials. E85 provides several advantages over traditional gasoline, but it also has some limitations that drivers should be aware of.

Key Facts about E85

  • 85% ethanol, 15% gasoline blend
  • Higher octane rating than regular gasoline
  • Renewable fuel made from corn and other plant materials
  • Typically cheaper per gallon than gasoline
  • Contains less energy than gasoline, resulting in decreased fuel economy

    Key Takeaways on E85

    To summarize key points about the E85 ethanol fuel blend:

    • E85 is an 85% ethanol, 15% gasoline renewable fuel option for flexible fuel vehicles
    • Benefits include higher octane, lower cost per gallon, and reduced emissions
    • Drawbacks include 25-30% lower fuel economy and less availability than gasoline
    • Only flex-fuel vehicles are designed for optimal E85 compatibility and performance
    • Drivers should weigh fuel economy losses against potential savings when considering E85
    • Proper maintenance and ethanol-compatible components are essential for trouble-free E85 use

How E85 Compares to Traditional Gasoline

E85 differs from traditional gasoline in a few key ways:

FeatureE85Regular Gasoline
Ethanol Content85%Usually 10% or less
Octane Rating100-10587, 89, 93
Energy ContentAbout 25% lessN/A
Fuel Economy25-30% lowerN/A
Cost Per GallonLowerHigher

The Pros of Using E85

There are some advantages to using E85 fuel:

  • Higher octane rating – The high ethanol content raises E85’s octane rating to between 100-105, compared to 87-93 for regular gasoline. This higher octane can improve performance in some engines.
  • Increased horsepower – In some cases, the extra octane in E85 allows engines to employ higher compression ratios safely, resulting in more power.
  • Cleaner emissions – E85 produces fewer smog-forming emissions than gasoline in most cases. Its high oxygen content helps engines burn fuel more completely.
  • Renewable fuel – E85 is made from renewable sources like corn and other plant materials. This can reduce dependence on fossil fuels like oil.
  • Lower cost – At the pump, E85 typically costs less per gallon than regular gasoline. However, lower fuel economy negates some of the savings.

The Cons of Using E85

There are also some potential drawbacks to using E85:

  • Reduced fuel economy – E85 contains about 25% less energy per gallon than gasoline, resulting in 25-30% fewer miles per gallon.
  • More frequent fills ups – The decreased fuel economy of E85 means you’ll have to refuel more often.
  • May not be suitable for all vehicles – Only “flex-fuel” vehicles are engineered to run optimally on E85. It could damage components or cause issues in other vehicles.
  • Less readily available – While gas stations offering E85 are increasing, it may still require going out of your way to fill up.
  • Cold weather starting issues – E85 is more difficult to vaporize for ignition when cold, so starting problems are more likely in cold weather.

What Vehicles Can Use E85?

Only flex-fuel vehicles (FFVs) are designed to operate on gasoline, E85, or any blend of the two. FFVs contain upgraded fuel system components designed to withstand the corrosive properties of ethanol. Here are some guidelines on E85 vehicle compatibility:

  • Most flexible fuel vehicles are labeled – FFVs have a yellow gas cap or yellow “Flex Fuel” badge near the fuel filler.
  • FFV options offered across brands – GM, Ford, Chrysler, Toyota, Nissan and others offer FFV models. Popular models include the Ford F-150, Chevy Silverado, and Dodge Ram pickup trucks.
  • Any model year FFV can use E85 – If a vehicle has the FFV designation, it can use E85 regardless of its model year. The FFV system does not wear out over time.
  • Only use E85 in FFVs – Putting E85 into a standard, non-flex-fuel vehicle risks damage, poor performance, and voided warranties.

How Does E85 Affect Performance?

Using E85 generally results in a decrease in fuel economy but offers some performance benefits:

  • Fuel economy drop of 25-30% – E85 contains less energy than gasoline, so fuel economy and range will decrease significantly.
  • More power in some engines – The higher octane rating allows some engines to operate at a higher compression ratio safely, resulting in more power.
  • Cold weather starting issues – E85 can be harder to vaporize and ignite in very cold temperatures, leading to potential starting issues. Additives can help.
  • Corrosion and debris concerns – Ethanol in E85 can produce debris that clogs filters and corrodes some fuel system components over time. periodic inspections are recommended.

Overall, use of E85 results in the classic trade-off between power and efficiency. Drivers prioritizing performance may accept the economy hit, while those seeking to maximize miles per gallon are better off with traditional gasoline.

Finding E85 Fueling Stations

The availability of E85 pumps continues to grow as demand increases:

  • Over 4,000 stations in the U.S. currently offer E85, mostly concentrated in the Midwest.
  • E85stations.com or the Open E85 app can help locate nearby E85 stations.
  • Look for yellow E85 decals or logos on gas station signs and pumps.
  • Costco offers E85 at many locations and tends to have the lowest prices.
  • Check if stations have dedicated E85 pumps, as blends can vary at multi-fuel pumps.

Though still outpaced by gasoline, E85 availability improves each year. Most major cities have multiple stations offering E85, with rural areas more sparse.
Finding E85 pumps can be challenging in some areas, but resources like the E85 Prices and Station Locator at Flexfuel.com make it easier. This continuously updated map shows E85 stations across the country and allows searching by location. Their station finder is a valuable tool for drivers wanting to fill up with E85.

Is E85 Worth the Cost?

Whether E85 is cost effective depends on your vehicle, driving habits, and fuel pricing:

  • Fuel economy loss negates savings – The 25-30% lower MPG on E85 versus gasoline means more fill-ups. In some cases, the fuel cost savings per gallon are outweighed by increased fuel usage.
  • High-performance engines benefit most – The maximal power gains of E85 are best utilized by modified sports cars and muscle cars, improving their acceleration and speed.
  • Long highway drives favor gasoline – E85’s economy disadvantage is amplified on long highway drives, while short city errands benefit more from lower pump prices.
  • Watch for price fluctuations – When gasoline prices spike, E85 can become more cost effective. But ethanol prices also fluctuate, influencing the savings.

For most drivers, choosing traditional gasoline or a 10% ethanol blend will provide the best value at the pump. E85 only delivers cost savings in specific scenarios with the right vehicle and driving habits.

Maintaining and Modifying Vehicles for E85 Use

Using E85 presents some special equipment considerations:

  • E85 compatible hoses and gaskets – Fuel hoses and seals should be made from ethanol-resistant materials to withstand corrosion. Nitrile rubber offers the best durability.
  • Stainless steel fuel lines – Stainless steel handles extended E85 exposure better than traditional steel fuel lines. This is recommended for dedicated E85 vehicles.
  • Higher flow fuel pump and injectors – More fuel is needed on E85, so upgraded fuel system components can optimize performance.
  • Flexible fuel sensor – This sensor detects the ethanol content and makes tuning adjustments, allowing the engine to adapt to any gasoline-ethanol blend.
  • Fuel tank and line coatings – Special EPA-approved fuel tank and line coatings, like fluoroelastomers, prevent corrosion issues.

For maximum reliability on E85, FFV-specific parts from the manufacturer are ideal. Third-party ethanol-compatible components also work well when OEM parts are unavailable.

Important Maintenance Tips for E85 Vehicles

E85’s properties call for some unique maintenance practices:

  • Change oil more frequently – Ethanol increases contaminant levels in oil, so shorter change intervals (5,000 miles or less) are recommended.
  • Inspect fuel lines and seals regularly – Look for leaks and change cracked lines/gaskets to head off problems.
  • Clean fuel injectors every 60,000 miles – Help remove deposits and buildup from injectors to maintain proper spray patterns.
  • Change fuel filter annually – Increased debris in the fuel can quickly clog filters, so change them yearly or more often if issues arise.
  • Use only ethanol-compatible components – Avoid non-ethanol-resistant hoses, gaskets, lines and coatings which can degrade over time.
  • Check for water in fuel – Ethanol attracts moisture, so periodically drain water from the fuel system to avoid corrosion damage.
  • Tune-ups every 30,000 miles – More frequent spark plug, wire and coil maintenance is advised to account for ethanol’s effects.

While E85 is compatible with FFVs on paper, taking the above proactive maintenance steps will help avoid frustrating and damaging problems down the line.

Is E85 Better for the Environment?

As a biofuel, E85 offers some environmental benefits compared to gasoline, but drawbacks exist too:


  • Made from renewable plant materials like corn, reducing reliance on fossil fuels
  • Lower lifecycle greenhouse gas emissions compared to gasoline
  • Produces fewer smog-forming pollutants than gasoline
  • Byproduct (distillers grains) used for livestock feed, reducing other impacts


  • More ethanol production increases demand for corn and other crops, impacting land use
  • Additional fertilizers and pesticides may be required to boost crop yields
  • E85 has lower fuel economy, requiring more fuel production per mile traveled
  • Emissions advantages can vary based on engine calibration and drive cycle

On the whole, using E85 likely provides moderate environmental improvements over conventional gasoline. But the net benefits are highly dependent on specific agricultural practices and vehicle tuning.

The Future of E85 and Ethanol Fuels

Several trends may shape the future of E85 availability and use:

  • Higher ethanol blend adoption – E10 and E15 blends are replacing pure gasoline at many stations, expanding ethanol acceptance.
  • Expanding E85 vehicle options – More flexible fuel options from automakers give consumers access to E85 capabilities in popular models.
  • Improved agricultural practices – Methods like precision farming, crop rotation, and cellulosic ethanol production can boost ecological benefits.
  • Fuel economy gains – Continued vehicle efficiency improvements can help counteract ethanol’s economy penalty.
  • Fuel pricing fluctuations – Gasoline and ethanol pricing shifts can significantly affect consumer interest in E85 based on cost.

While E85 uptake remains relatively low now, wider ethanol adoption, expanding vehicle options, and improved agricultural practices may move it more into the mainstream in the coming decades.

With lower pump prices but reduced range, E85 offers both advantages and compromises vs. gasoline. Drivers interested in this renewable fuel option should educate themselves on the pros, cons, vehicle compatibility, and proper car care practices to make an informed choice.