Unless you drive an electric car, you might wish you could do more to slow the environmental impacts of driving your liquid-dinosaur-burning vehicle. Some people have shifted to buying hybrids, which use electric motors and batteries to supplement the gas-burning engines, while others have shifted the kinds of fuel they burn altogether. That’s where flex fuel vehicles (FFV) come in.

Flex fuel vehicles are very similar to normal vehicles, but they have powertrains that have been specifically designed to run blended fuel that contains higher levels of ethanol. That fuel, called E85 in most places, is a mixture of alcohol (ethanol, in this case) and traditional gasoline.

Depending on where you live in the world, your experience finding E85 fuel might be as simple as a trip to the corner gas station or as complicated as an internet search for E85-friendly stations. The questions surrounding E85 and its uses could stretch on for days, and we’re here to answer the most pressing of the bunch. Let’s dive into the wild and wacky world of E85.

How Does E85 Actually Work?

E85 fuel, also known as flex fuel, is a blend of ethanol (alcohol) and gasoline. The mixture usually contains somewhere between 51 and 83 percent ethanol, but the exact ratio will depend on the season and geographical location.

Ethanol is a corn-based alcohol that can provide several potential benefits that include fewer emissions, higher resistance to engine knock, and a minor reduction in the United States’ demand for oil. It burns in an engine just like gasoline but has to be mixed with gas to allow starts and to regulate performance in cold weather.

What’s the Difference Between E85 and Normal Gas?

Gasoline is refined from crude oil that was gathered from the earth through one of many drilling and extraction processes. Ethanol, which is the “E” in E85, is an alcohol that usually comes from corn fermentation.

Can I Run E85 In My Normal Car or Truck?

We’re not going to advocate for its use in vehicles that weren’t designed to handle it. You should always use the fuel that your vehicle manufacturer calls for, not whatever you feel like or think is interesting.

What Will Happen If I Do?

There’s a good chance that you won’t notice anything immediately if you decide to fill up with E85. Even so, using ethanol in a non-flex-fuel-equipped vehicle can create issues, which we’ve outlined below, over time.

  • Potential Engine Damage

Ethanol can erode or damage engine internals that are not designed to work with it. Your vehicle’s engine components can be susceptible to damage if they’re not the right materials or configurations to handle flex fuel.

  • Check Engine Light

Your car may think something is wrong after a fill-up with E85 because the reduction in emissions could trigger a lean warning in the engine control unit, causing a potential adjustment to the air-fuel mixture.

  • Loss Of Fuel Economy

Ethanol is less energy-dense than gasoline. This means that your car will have to burn more of it to achieve the same result.

  • No Financial Benefit

Using E85 in a non-flex-fuel vehicle isn’t going to save you any money. Any cost-benefit at the pump will be wiped out by a reduction in fuel economy. With the risk of potential engine damage over time and an annoying check engine light, there’s really no reason to risk it.

Car Bible’s Glossary for E85

Educate yourself.

  • Fuel Economy

Fuel economy refers to the distance that can be traveled by a vehicle using a single gallon of fuel. We use this term here as a way to illustrate the differences between E85 and gasoline. E85 is less energy-dense than standard gas, so it takes more of it to produce the same result.

  • Emissions

Emissions refer to the amount of pollutants that your vehicle produces in everyday operation. This can include everything from carbon monoxide to particulate matter that is burned and released into the air.

  • Engine Knock

Engine knocking occurs when some of the air-fuel mixtures in the combustion chamber is ignited outside of the spark provided by the spark plug.

Your Questions, Our Answers on E85

Your burning questions answered.

Q: Is E85 More Expensive Than Gas?

A: E85 is usually cheaper per gallon than gasoline, but because of its composition, it’s more expensive than gas per mile to operate the vehicle.

Q: How Can I Know If My Car Is Flex Fuel Ready?

A: This will depend on the vehicle, but in most cases, you’ll be able to find the recommended fuel type listed out inside the fuel filler cover. This will tell you if your vehicle requires premium fuel, or if it can run E85. You can also look for badging or yellow tags.

Q: Where Can I Find E85?

A: According to, there are over 3,500 E85 fueling stations located across 42 states. You can see the government search tool here.

Q: Can I Mix E85 With Regular Fuel?

A: You absolutely can, but there’s no practical benefit to doing so. If you have to fill up with one or the other, there’s nothing to worry about, as long as your vehicle is equipped to handle E85 to begin with. Just don’t make a habit of it.

Video on E85

Car Bible’s Recommended E85-Related Products

You can buy tools for flex fuel vehicles at almost every auto parts and home improvement store, as well as online stores like Amazon. You have a sea of options to select from. We picked two we think you’d benefit from, the REV X E85 Test Kit and AEM E85-Compatible Fuel Pump. They’re affordable, reliable, and should handle the job well. We also realize that it might be out of stock, which means we’d have to choose our runners up, the Evil Energy 20ft E85 Fuel Line.

Disclosure: is also a participant in the Amazon Services LLC Associate Programs, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Pages on this site may include affiliate links to Amazon and its affiliate sites on which the owner of this website will make a referral commission.