What is E85 Fuel? Complete Guide to Flex Fuel
E85 is a high-octane flex fuel blend containing up to 85% ethanol. It offers a renewable, cost-effective alternative for flex fuel vehicles. Here is everything you need to know about E85 fuel, from octane ratings to compatibility and delivery.
What Is E85 Fuel?
E85 is a fuel blend consisting of approximately 85% denatured ethanol and 15% gasoline. The exact ethanol percentage varies seasonally — in warmer months, E85 may contain as much as 83-85% ethanol, while winter blends can drop to 51% ethanol to improve cold-start performance. The "E85" designation refers to the maximum ethanol content, not a fixed ratio.
Ethanol in E85 is produced primarily from corn in the United States, though sugarcane-based ethanol is also used in some regions. The fuel is classified as a renewable energy source because its feedstock — corn or sugarcane — can be regrown each season, unlike petroleum which takes millions of years to form.
E85 carries an octane rating of approximately 100-105 AKI (Anti-Knock Index), making it one of the highest-octane fuels available at retail. For comparison, premium gasoline in Florida is rated at 91 AKI. This high octane rating means E85 resists pre-ignition (knocking) extremely well, which is why it is popular in high-performance and racing applications where engines are tuned for maximum power output.
Which Vehicles Can Use E85?
E85 can only be used in Flex Fuel Vehicles (FFVs) — vehicles specifically engineered to run on any blend of ethanol from E10 (10% ethanol) up to E85. FFVs have modified fuel systems including corrosion-resistant fuel lines, a specially calibrated fuel injection system, and an ethanol sensor that adjusts the air-fuel mixture automatically based on ethanol content.
You can identify a flex fuel vehicle by its yellow gas cap, a badge or emblem on the vehicle (often reading "Flex Fuel" or "E85"), or by checking your owner's manual and the VIN decoder at fueleconomy.gov. Major manufacturers including Ford, GM, Chrysler, and Toyota have produced FFV models across their truck, SUV, and sedan lineups.
Using E85 in a vehicle that is not a designated FFV can cause serious damage. Ethanol is corrosive to standard fuel system components — rubber seals, gaskets, and fuel lines in non-FFV vehicles will degrade. The engine computer cannot compensate for the drastically different air-fuel ratio, which can lead to lean running, misfires, overheating, and catalytic converter damage.
Pros and Cons of E85
The advantages of E85 are significant for the right application. E85 typically costs $0.50 to $1.00 less per gallon than regular gasoline. Its high octane rating (~105 AKI) allows engines tuned for E85 to produce more power than on regular gasoline. E85 burns cleaner, producing fewer carbon monoxide and particulate emissions. And because ethanol is derived from renewable crops, E85 reduces dependence on foreign petroleum.
The primary disadvantage of E85 is lower energy content. Ethanol contains approximately 76,000 BTU per gallon compared to gasoline's 114,000 BTU per gallon. This means E85 delivers 25-30% fewer miles per gallon than regular gasoline. A vehicle that gets 30 mpg on regular gasoline might only achieve 21-23 mpg on E85. Depending on the price differential, E85 may or may not save money on a cost-per-mile basis.
E85 availability is more limited than regular gasoline. While Florida has E85 stations in major metro areas — Tampa, Orlando, Miami, Jacksonville — rural stations often do not carry it. E85 also has a shorter shelf life than gasoline due to ethanol's hygroscopic nature (it absorbs moisture from air), which can cause phase separation in storage tanks if not managed properly.
E85 Availability in Florida
Florida has a growing network of E85 fueling stations, concentrated primarily in the Tampa Bay area, Orlando metro, South Florida, and Jacksonville. As of 2025, the U.S. Department of Energy's Alternative Fuels Station Locator lists over 60 E85 stations across the state. However, availability is still limited compared to conventional gasoline, particularly in rural counties and the Panhandle region.
For fleet operators running FFV vehicles in Florida, retail E85 stations present logistical challenges — station locations may not align with routes, and pump speed at retail stations is slow for bulk fueling. BettyJet solves this by delivering E85 directly to your fleet yard, job site, or facility, eliminating the need for drivers to seek out E85 stations.
E85 vs Regular Gasoline (87 Octane)
| Property | E85 Flex Fuel | Regular 87 Gasoline |
|---|---|---|
| Octane Rating (AKI) | 100-105 | 87 |
| Energy Content (BTU/gal) | ~76,000-84,000 | ~114,000 |
| Fuel Economy Impact | 25-30% fewer MPG | Baseline |
| Typical Price | $0.50-$1.00/gal less | Baseline |
| Emissions | Lower CO & particulates | Standard |
| Vehicle Requirement | FFV only (yellow cap) | Any gasoline vehicle |
| Renewable Content | 51-85% ethanol | Up to 10% ethanol (E10) |
| Florida Availability | Limited (~60 stations) | Widespread |
Who Uses E85 Fuel?
Fleet Operators with FFVs
Companies running flex fuel trucks, vans, and sedans can reduce fuel costs by 10-15% with E85 while meeting sustainability goals.
Government & Municipal Fleets
Federal, state, and local government fleets are mandated to use alternative fuels when available. E85 is the most accessible option for FFV fleets.
Performance & Racing
E85's high octane rating makes it a preferred fuel for drag racing, autocross, and tuned performance vehicles where maximum power is the priority.
Agriculture Operations
Farm operations running FFV trucks and utility vehicles can leverage E85 cost savings while supporting the corn-based ethanol industry.
Learn more →How BettyJet Delivers E85
BettyJet delivers E85 flex fuel directly to fleet yards, job sites, and commercial facilities across Florida. Our tanker trucks are equipped with dedicated compartments for E85 to prevent cross-contamination with other fuel types.
We offer scheduled recurring deliveries for fleet operators who consume E85 regularly, as well as on-demand delivery for one-time or occasional needs. Minimum order is typically 500 gallons. Most deliveries are completed within 48 hours of order placement.
Every E85 delivery includes documentation of ethanol content percentage and meets all applicable ASTM D5798 specifications for fuel ethanol blends. Contact BettyJet at (813) 694-8898 or request a quote online to get E85 delivered to your location.
E85 Fuel Frequently Asked Questions
What does E85 stand for?
E85 stands for a fuel blend containing up to 85% ethanol and 15% gasoline. The 'E' refers to ethanol and the '85' refers to the maximum percentage of ethanol in the blend. Actual ethanol content varies seasonally from 51% to 85%.
Can I put E85 in any car?
No. E85 can only be used in Flex Fuel Vehicles (FFVs) specifically designed for high-ethanol blends. Using E85 in a standard gasoline vehicle can damage fuel lines, seals, injectors, and the catalytic converter. Check for a yellow gas cap or 'Flex Fuel' badge on your vehicle.
Is E85 cheaper than regular gas?
E85 is typically $0.50 to $1.00 cheaper per gallon than regular gasoline. However, because E85 contains less energy per gallon, your fuel economy drops 25-30%. On a cost-per-mile basis, savings depend on the current price spread between E85 and regular gasoline in your area.
Does E85 damage engines?
E85 does not damage engines in Flex Fuel Vehicles, which are engineered for it. In non-FFV vehicles, E85 can corrode fuel system components and cause engine damage. The ethanol in E85 is a solvent that attacks rubber, plastic, and certain metals used in standard fuel systems.
Does BettyJet deliver E85 in Florida?
Yes. BettyJet delivers E85 flex fuel across Florida to fleet yards, commercial facilities, and job sites. Minimum order is 500 gallons with standard 48-hour delivery. Call (813) 694-8898 or visit bettyjet.com/get-a-quote for pricing.
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