Why is there ethanol in our gasoline? | Fuel Facts

Photography Credit: Robin Vet

Is that 10% ethanol found in most pump gasoline good or bad for your classic? Like many things in life, it’s complicated. 

Why Is Ethanol in Gasoline?

Back in olden times–up until the ’70s–lead was added to gasoline to increase its resistance to knock. This tetraethyllead was found to cause smog and other issues, however, so it was eventually banned from pump gasoline. To further help reduce smog, in the ’80s an oxygenate called methyl tert-butyl ether, also known as MTBE, was added to gasoline. 

Small problem with MTBE: As noted by Zachary J. Santner, technical specialist at Sunoco Race Fuels, MTBE has a “low threshold to be detected by nose and taste.” In other words, a little goes a long way as far as making groundwater smell bad. 

Today, ethanol is used to elevate the octane of pump fuel. The 87- and 93-octane grades regularly found at the pump, Santner explains, leave the pipelines with 83 and 90 octane ratings, respectively; it’s that 10% or so of ethanol added at the distribution terminals that increases the octane to its final values. 

But don’t think of ethanol as a cheap fix: The science says that ethanol also increases horsepower. In fact, Santner notes, when NASCAR Cup teams moved from ethanol-free fuel to Sunoco Green E15, a product containing 15% ethanol, all of the teams were able to retune for more horsepower. In the most basic science terms, extra oxygen means extra horsepower. 

Why Is Ethanol in Fuel an Issue Now?

The calendar on the wall says that winter is getting closer by the day, meaning many classics will soon begin hibernating for a few. 

Another feature of ethanol: It’s hygroscopic, meaning it can absorb moisture from the atmosphere. For most motorists, that’s not an issue because they use up the fuel soon after purchase. The problem arises when ethanol-enriched fuel is allowed to sit for a while. 

The easiest fix for winter: Fill up with ethanol-free fuel. Sunoco offers Optima, an ethanol-free fuel designed for storage, while local options can be found at pure-gas.org. If you can’t obtain this type of fuel, Santner adds, a higher-octane gasoline will age better than a lower-octane product.

Join Free Join our community to easily find more Sunoco, Sponsored Content, Fuel Facts and Ethanol articles.
More like this
Comments
Bardan
Bardan New Reader
1/26/21 3:26 p.m.

Ethanol was used to promote corn sales in the midwest. It's political! 

300zxfreak
300zxfreak Reader
1/27/21 2:24 p.m.

In reply to Bardan :

You are exactly correct, there is no other reason for ethanol in our gasoline, pseudo science notwithstanding. The politicos would have you believe that it's there to stretch our gas/oil reserves. Hogwash, the amount of ethanol in our gas wouldn't stretch granny's girdle. It's simply that the farmers have a strong lobby in DC and are looking to increase the use of ethanol even further. Don't get me wrong, I love our farmers, they're one great group of people, but shoving ethanol down our fill tubes does not make anyone happy except them and their paid shills.  End of soapbox rant.

 

frenchyd
frenchyd UltimaDork
1/27/21 3:35 p.m.
300zxfreak said:

In reply to Bardan :

You are exactly correct, there is no other reason for ethanol in our gasoline, pseudo science notwithstanding. The politicos would have you believe that it's there to stretch our gas/oil reserves. Hogwash, the amount of ethanol in our gas wouldn't stretch granny's girdle. It's simply that the farmers have a strong lobby in DC and are looking to increase the use of ethanol even further. Don't get me wrong, I love our farmers, they're one great group of people, but shoving ethanol down our fill tubes does not make anyone happy except them and their paid shills.  End of soapbox rant.

 

It's simpler than that.  What is the first primary election on the way to the White House?  Yep it's that simple.  
   Now is ethanol good or bad?  
It's wonderful at making power.  Indy cars use 100% ethanol. They used to use 100% methanol which is slightly more powerful. But that stuff is nasty deadly. Get it on your skin it and attacks internal organs. Breath it and it attacks your lungs. 
     Ethanol on the other hand is what's in beer, wine and booze.  Drink ethanol and you get happy. Drink Methanol and you die. 
Ethanol does a wonderful job of cleaning crud and deposits.  It also make the engine run cooler.   it won't hurt any rubber used on a car in this century or much of the last for that matter

Now the facts about Ethanol and our classic. Cars. Alcohol attracts water. Absorbs it out of the air. But Gasoline has always had some water in it. Cars from the 40's early 50's often had a glass bowl so you could actually see how much water was in the gas.  A little bit of water helps, it cleans plugs and etc. If your cars electrical system is good notice how much nicer, smoother a car runs on a rainy day.  
      Yes there are additives like Stabil that help with water absorbing.  But if you aren't going to use your car for more than a month you are probably better off storing it with non oxygenated fuell. 

frenchyd
frenchyd UltimaDork
1/27/21 5:34 p.m.
300zxfreak said:

In reply to Bardan :

You are exactly correct, there is no other reason for ethanol in our gasoline, pseudo science notwithstanding. The politicos would have you believe that it's there to stretch our gas/oil reserves. Hogwash, the amount of ethanol in our gas wouldn't stretch granny's girdle. It's simply that the farmers have a strong lobby in DC and are looking to increase the use of ethanol even further. Don't get me wrong, I love our farmers, they're one great group of people, but shoving ethanol down our fill tubes does not make anyone happy except them and their paid shills.  End of soapbox rant.

 

Well you can complain about Ethanol or you can take advantage of the extra power it makes.  According to actual GRM tests E85 makes more horsepower than race gas. Seriously more.  
    I have a flex fuel Ford pickup. My seat tells me that there is a lot more power. But it does cost me in fuel mileage. I get about 22 MPG. With my 2016 F150 V8 4x4  

When  I use E85 I get about 2MPG  less but right now gasoline sells for $2.29/9 a gallon. But E85 sells at the same place for $1.64/9 a gallon  

It works out that I save about $5 a tankful and have more power.  Cheaper and better. Thank You tax payers. 

84FSP
84FSP UltraDork
1/27/21 6:35 p.m.

The latest tune for V is all setup on E85 ala the bigger injectors, flex  fuel sensor, and bigger pump.  It costs me about 4mpg but I'm way ahead on filling up cost at 1.70 vs 2.90.  

It felt better everywhere in the rpm band but didn't show any peak power gain despite exhaustive tuning efforts on the dyno.  I decided to give 93 a go again the other day to verify with the old butt dyno.  The E85 ran noticeably better all throughout the range and had noticeably more grunt from 2k to 6k.  Strangely it just has better manners at idle etc.  

Corn fan for life.

CJ (FS)
CJ (FS) HalfDork
1/27/21 6:35 p.m.

Two words - Corn Lobby

300zxfreak
300zxfreak Reader
1/27/21 9:19 p.m.

In reply to frenchyd :

I'll give you that you'll see power with the proper tune, but I'm not about to run that much ethanol through the fuel system on a 30 year old Z, can't see anything good coming from that.

frenchyd
frenchyd UltimaDork
1/27/21 9:46 p.m.

In reply to 300zxfreak :

I agree,  it will clean all the accumulated crud and residue. 
    If there isn't a good fuel filter system just keep running it until it catches up to you and stops you someplace.  Then you can take it apart and clean it by hand. 
     You might get lucky and it won't happen during your ownership. Stranger things have happened. 
Besides if you have a fuel cell the foam will need to be updated. ( it's supposed to be every 6 years anyway ) 

Goluscombe
Goluscombe New Reader
11/22/21 1:37 p.m.

Not only did the farm lobby influence (Oh, I'm sorry, it's really just those ever-neccessary campaign donations given out of the goodness of their hearts.)  our politicians, it's realy not a good way to reduce pollution and reduce green house gases.  

For our common auto gas, it takes one unit of energy to make eight units comong from the ground to the pump.   For corn grain alcohol it takes seven units of energy to make eight.   I understand that this is because of the enrgy needed to make nitorgen fertilizer and for the traveling by truck to move all the components needed to make and produce alcohol.      

While alcohol in the fuel provide an opportunity to increase horsepwoer, it's less energy dense creating less power per gallon of gase.  This means a greater volume of fuel will be needed for the same horsepower.   Put another way, your fuel mileage goes down accordingly when greater fractions of alcohol are mixed into gasoline.  

Other than that, it's pretty good stuff.

 

 

 

NOHOME
NOHOME MegaDork
11/22/21 3:57 p.m.

Nothing but pork barrel politics. But that is nothing new and something that is not ever going to go away. Electric cars are the same deal but different. 

You'll need to log in to post.

Our Preferred Partners
ANPa8TRoBENomJYLHWiaFStGqkPIVGlhr3gh5Dt5UGMRg0AlKGwmZymlilMFAjJx