Under the Hood: What is E85?

Under the Hood: What is E85?

AutoGuide’s regular “Under the Hood” segment has already explained the vagaries of octane and the advantages of Top Tier gasoline, but there’s so much more to fuel than that. Ethanol, for instance, is a major component of gas, and something that’s a potential peril for consumers. But what is ethanol? And what is E85? Should you run these fuels in your vehicle?

Simply put, E85 is gasoline that’s been blended with ethanol. It’s 15 percent gas and 85 percent alcohol. See where the name comes from? It’s an alternative fuel, and arguably the most successful one available in America today. Competitors like compressed natural gas and bio-diesel have not come close to the impact ethanol has made.

1923-Ford-Model-T.jpgE85 sounds like a relatively new thing, as many drivers are unfamiliar with it, but the idea of using ethanol alcohol as a transportation fuel is far from new. According to Robert White, Director of Market Development for the Renewable Fuels Association, “it wasn’t until 1998 that automakers started to make what we call flex-fuel vehicles,” but ethanol has been used for decades before that. Henry Ford even designed the Model T to run on alcohol.

The Renewable Fuels Association is a national trade group for ethanol producers. It’s a non-profit based in Washington D.C. that’s been around for more than 30 years.


Ethanol-Corn-Moonshine.jpgLike top-shelf Scotch Whiskey or bargain-basement vodka, ethanol is basically a grain alcohol, and one you could drink. But don’t EVER think of bellying up to your local gas pump. Fuel-grade ethanol has literally been poisoned to prevent would-be partiers from getting a cheap buzz. Put your shot glasses down and step away from the filling nozzle.

The alcohol in American E85 is generally made from corn. The starch within each kernel is converted to sugar; the sugar then gets mixed with yeast and water and is allowed to ferment. After that it gets distilled, where the end product is 200-proof grain alcohol. Think of it as industrial moonshine. Later it gets mixed with a denaturant – the poison mentioned in the paragraph above – as well as gasoline to make the blended fuel sold at stations across the country.


Brazil-Flag.jpgIf there’s one nation that’s synonymous with ethanol it’s Brazil, and by a long shot. “They’re at it for 33 years now,” White said, noting “[they] got a very early head start on us under a military dictatorship.”

The South American country has been promoting the use of ethanol for decades. Gas stations typically offer several options ranging from “gasohol” blends with ethanol levels around the 20 percent mark, to E85, to pure alcohol.

One contrast between the United States and Brazil is that American ethanol is overwhelmingly made from corn. Thanks to a tropical climate, Brazil’s is sourced from sugarcane.

Despite these factors, the U.S. actually produces more ethanol than its southern-hemisphere rival. According to White, it’s estimated American companies will produce more than 13 billion gallons of it this year.


Ethanol is a renewable fuel, one derived from plants. Unlike oil, coal or natural gas it can grow back every year, but that’s not the limit of its benefits.

“It’s a domestic product – more jobs for Americans – it’s not coming from overseas on supply routes we’re protecting with our military,” White said. Also, he said ethanol has the potential to drastically reduce emissions because on a molecular level it contains more oxygen than gasoline. This allows it to burn more thoroughly inside an engine.

Additionally, “E85 has a very high octane level” White said. It’s typically rated anywhere from 96 to about 105 on America’s (R+M)/2 scale. Straight alcohol performs even better, clocking in at 113. Premium-grade gasoline by comparison usually only has a rating of 93. This octane boost is something automakers have yet to take advantage of.

SEE ALSO: Under the Hood: What is Octane?

“I think a big help would be to have the vehicles more engineered for the fuel,” White said. They could be optimized to run on high-octane, high-ethanol fuel and make a lot more power in the process. “Still, today, we have vehicles that are engineered for clear gasoline – E0 – yet over 95 percent of all fuel sold is E10.” If you haven’t guessed, E10 is gasoline blended with 10 percent ethanol.

Aside from a potent, renewable, domestic source of energy, ethanol has at least one more trump card in its hand: distiller’s grain, a valuable leftover from the production process. White said it looks like fine flour and that it’s just “fat, fibers and oils laying there without starch.” Remember, the grain’s starch was converted into sugar, which was fermented into alcohol. He said “the vitamins, fats and oils can come back out for animal feed,” a saleable byproduct.



Of course there are downsides and tradeoffs to everything and ethanol is no exception. One of the biggest hurdles it has to overcome is availability. White said there are only about 3,000 gas stations in the U.S. that sell E85, an impressive-sounding figure until you compare it to the total number of fueling locations in the country. Today that figure is right around 160,000. Ouch.

Another downside is fuel economy. “It has lower thermal efficiency so your range is always going to be less than gasoline” said Jim Hall, Managing Director of 2953 Analytics, adding “there’s no way around that.”

Corn-Field.jpgThe U.S. Department of Energy (DOE) estimates that when E85 is used in vehicles designed to handle it, drivers will experience a 25 to 30 percent drop in fuel economy because it is less energy dense than gasoline. White disagrees. Speaking from personal experience he said the loss is “usually between 15 and 20 percent” a significant reduction to be sure, but not as severe as Uncle Sam claims.

Ethanol also faces trouble at gas stations. “There’s nothing that pushes people to the E85 pump” White said because they’re inclined to use what they’ve been running for years – regular gasoline. Station owners find it hard to justify the expense of installing new pumps dedicated to E85. Hall said “it’s always tough to replace the established technology.”

There are other issues, too. White said “[there’s] a huge disconnect when you got down to the dealerships,” adding that salespeople rarely push flex-fuel vehicles. He said 50 percent of the cars and trucks produced by the Detroit Three can run on E85, but good luck finding a dealer that will point it out.

With all of this ethanol talk there’s one critically important thing to mention. If your vehicle is not specifically designed to handle E85 DO NOT USE IT. Ethanol can be corrosive to fuel lines. It can also deteriorate seals and O-rings leading to expensive repairs. A gallon or two may not cause any harm but long-term use will certainly cause damage.  Exercise caution at the gas station and always double check you’ve grabbed the correct dispenser. E85 nozzles are typically bright yellow.


Some people are worried ethanol is cutting into the food supply, a legitimate concern. According to the United States Department of Agriculture (USDA) in 2010 13.2 billion gallons of corn-based alcohol were produced in the U.S., a figure that accounted for nearly 40 percent of the nation’s crop. Still, those billions of gallons of ethanol replaced some 445 million barrels of imported oil.

Corn is used in practically everything from soft drinks to animal feed. Increasing global demand for this commodity grain – both as a fuel and a food – will naturally have an impact on its price and availability.

Downplaying these concerns, White said modern farmers are phenomenally productive and that there are actually fewer acres of corn planted today than in the 1930s. They’re producing more grain using fewer resources. They’ve also implemented more responsible farming techniques. He said “the fertilizer used per acre has dropped 30 percent over the last decade.”

E85-Logo.jpgDRUNK ON OIL

Ethanol could be the eco-friendly fuel of the future. As controversial as it is, even corn-based alcohol is offsetting significant amounts of oil and that is a step in the right direction. As it was in the early days of the automobile, ethanol is incredibly promising.

Every red-blooded, gun-totin’, beef-eatin’ ‘Merican loves a good V8 engine, and this fuel could satisfy our lusty automotive desires in a responsible, sustainable manner. What’s better than having your cake and eating it too? Owning the bakery and not getting fat from all the carbohydrates. When it comes to fuel that’s just what ethanol promises.

  • smartacus

    Craig Cole: With the recent shootings still fresh in the news cycle; please be more careful with insensitive wording like red-blooded and gun-totin’ ‘Merican because it hurts.  I don’t want to read words like this one day after Christmas.