what is the effect of 10% ethanol in premium?

TorqueJunkie

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Ethanol does have a static octance rating somewhere in the 108-110 range, but adding 10% will not really affect the octane rating all that much. People claim fewer MPG and HP because the higher octane rating requires more heat to light, which equivicates to being a little harder for the engine to ignite it. It is added because it does not require fossel fuel to create it and it burns cleaner. So it is better for the environment and is a step in the right direction on getting us off of our dependency towards fossel fuels.
 

Chuck 98 RT/10

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It depends on what the engine was designed for. But hasn't ethanol been added to all gas for years now? If so, I'm betting Detroit has engineered for it.
 

fluffy

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The lower MPG and HP from ethanol is very real, and has nothing to do with the octane and everything to do with lower energy content (gallon for gallon) of ethanol vs gasoline. Ethanol contains about 66% as much chemical energy as gasoline: 76,000 BTU/gallon (low heat value basis) vs 114,000 BTU/gallon. The lowering of the energy content of the tank results in more fuel being injected into the engine to compensate, which lowers fuel efficiency.

If you can possibly avoid it, do so. Our cars will run on it, but you can't change the laws of thermodynamics: less total energy in the tank means less power and lower efficiency. You will burn more to do less.
 

Snakester

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Actually, you are both right. Ethanol has a higher octane rating, but lower energy content.
We have been using it in California for years now in all gasoline blends because it does burn cleaner. MTBE was added years ago to compensate for pulling lead out of gasoline, and MTBE was replaced by ethanol since 2004 here.

The hit in gas mileage should be pretty small with the standard 10% blend, and HP should be comparable.
 
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Flyntgr

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If I did my math right, which would be a small miracle, I get 6.67% less horsepower and torque on gasoline with 10% ethanol (66% X 10% = 6.67 %). Is this correct? I'm interested for dynomometer reasons, not greenpeace considerations. Thanks.!
 

Tom F&L GoR

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Dudes:

The octane of an ethanol blend is exactly what is says on the pump. When the fuel is blended, the 90% gasoline portion (known as RBOB, now listed on the commodity exchange) is adjusted so that the additional 10% ethanol returns it to the posted number. You are not getting more or less octane than with a 100% gasoline.

The blend may give you a teeny bit more power because the latent heat of vaporization (cooling effect) will provide a slightly denser charge to the combustion chamber. Put alcohol on your skin - feels cold when it evaporates? Same thing happens to the intake charge.

The blend of 10% ethanol has ~3% oxygen delivered via the ethanol, and therefore ~3% less energy. You should get ~3% less fuel economy (in a very basic comparison.) But it gets lost in the details such as the comment above.

You should get 0% less power because the oxygen sensors in the exhaust will compensate for the lower energy density. At full throttle, if the system is in open loop, then you are rich anyway.

The math example would therefore not apply. If it did, it would be 33% of the 10% is oxygen instead of fuel, and a 3.3% power decrease. But it doesn't work that way.

The only practical difference is that alcohol forms deposits on valves and intake ports to a far, far greater degree than gasoline. You would be safe to use a bottle of a reputable intake system cleaner (not injector cleaner) once every oil change, in the tank before you change the oil.
 

Coloviper

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Waiting for the first flex fuel E-85 Viper to come out? :) Not now, but it will eventually happen! Basically everything will be changing in the future and there will be a brief period where the cars will **** once again (circa mid 1970s and early 1980s) and then the power will come back up (like today's muscles cars, when everyone is rejoicing) and everyone will be happy again.

I am not even sure you can buy a non Ethanol blend gas here in Colorado, other than 100 Octane Racing fuel, of which in time, kiss your O2 sensors and cats goodbye. Even worse here with the high oxygenated fuels of the winter. Power and MPG both go down. Then again we are working on a one mile restrictor to start with.

Ethanol is here to stay, so we might as well just accept that and start work with it instead of against it. It is a proven technology with over 25 years of real world usage without failure. I remember living in Canada 25 years ago and using Ethanol blended fuels back then. Why it has taken this long to perculate through America is a mystery to me?

I guess to answer your question, it is, what it is.
 

Tom F&L GoR

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>Power and MPG both go down. <

In a car with fuel injection and feedback, power should not change.

MPG would decrease by 3% at most. That's 10 MPG to 9.7 MPG...

Ethanol has had a huge share of problems. It attracts water, causes rust, and carries all sorts of things with it into your gas tank. It is still shipped separately to the local terminals and only blended into gasoline there or in the tanker that delivers it to the station. One reason it's economically kind of silly is that it can't go in the same pipelines that distribute gasoline, heating oil, jet fuel, kerosene, and everything else. It has created a complete new, duplicate distrubution system.
 

fluffy

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It also pollutes more than pure gasoline, is more expensive to produce, has almost no net energy gain, and even if the entire land area of the United States were devoted to growing corn solely for ethanol use, we still wouldn't have enough to supply our fuel needs.

Ethanol is a dead end; it always has been, really. In no way, shape or form is it better than gasoline. It's just hyped right now.
 
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Chuck 98 RT/10

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It also pollutes more than pure gasoline, is more expensive to produce, has almost no net energy gain, and even if the entire land area of the United States were devoted to growing corn solely for ethanol use, we still wouldn't have enough to supply our fuel needs.

Ethanol is a dead end; it always has been, really. In no way, shape or form is it better than gasoline. It's just hyped right now.

Propaganda from the evil oil companies and Jack Daniels.
 

Shandon

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So how do we find out who has 93 Octane without 10% ethanole? Is there gas stations that use it and some that don't? Or is it state by state and then what state has what?
 

fluffy

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It can be state by state, or on a station by station basis where there is no state requirement. Here in Massachusetts I only have access to E10, so that's what I use.

Generally stations will post the alcohol content of their fuel at the pump (and it may be required, I don't know); we have stickers that say "Fuel may contain up to 10% ethanol by volume" or some such, so it's easy to see who is using it.

Currently at least Minnesota, Hawaii, Montana, Washington, Colorado, Illinois, Iowa, Kansas, Missouri, Michigan and New Mexico have mandated ethanol blends for all gasoline sales (though most of the mandates have not yet taken effect). That data is a bit old too, so there are probably others who have started down the dark road.
 

Racer Robbie

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>Power and MPG both go down. <

In a car with fuel injection and feedback, power should not change.

MPG would decrease by 3% at most. That's 10 MPG to 9.7 MPG...

Ethanol has had a huge share of problems. It attracts water, causes rust, and carries all sorts of things with it into your gas tank. It is still shipped separately to the local terminals and only blended into gasoline there or in the tanker that delivers it to the station. One reason it's economically kind of silly is that it can't go in the same pipelines that distribute gasoline, heating oil, jet fuel, kerosene, and everything else. It has created a complete new, duplicate distrubution system.

Tom, Here is a wonderfull article from Starbrite on this problem.

http://www.starbrite.com/whatsnew/STAR%20BRITE%20ethanol%20p3072D2.pdf

Robbie
 

Steve-Indy

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Sorry, Chuck...but did you catch this article???

Ethanol-Fueled Vehicles Could Pose Health Risk
Tracy Hampton, PhD

[FONT=verdana, arial, helvetica, sans-serif]JAMA. 2007;297:2068. [/FONT]
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[FONT=Verdana, Arial, Helvetica, sans-serif][SIZE=-1]Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.[/SIZE][/FONT]
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In the hunt for alternative fuels, scientists have touted ethanol as a promising candidate. But a recent study cautions that if every vehicle in the United States ran on ethanol instead of gasoline, the number of respiratory-related deaths and hospitalizations would likely increase (Jacobson MZ. Environ Sci Technol. doi:10.1021/es062085v [published online April 18, 2007]).
In the study, Mark Jacobson, PhD, of the department of civil and environmental engineering at Stanford University, in Palo Alto, Calif, used computer simulations of atmospheric conditions in the United States in 2020, with a special focus on Los Angeles, to compare 2 future scenarios: if all vehicles were fueled by gasoline vs if they were powered by E85, a popular blend of 85% ethanol and 15% gasoline. Jacobson's model accounted for the transport of tailpipe emissions across the country, as well as chemical transformations in the atmosphere. Jacobson found that E85 . . . United States ran on ethanol instead of gasoline, the number of respiratory-related deaths and hospitalizations would likely increase (Jacobson MZ. Environ Sci Technol. doi:10.1021/es062085v [published online April 18, 2007]).

In the study, Mark Jacobson, PhD, of the department of civil and environmental engineering at Stanford University, in Palo Alto, Calif, used computer simulations of atmospheric conditions in the United States in 2020, with a special focus on Los Angeles, to compare 2 future scenarios: if all vehicles were fueled by gasoline vs if they were powered by E85, a popular blend of 85% ethanol and 15% gasoline. Jacobson's model accounted for the transport of tailpipe emissions across the country, as well as chemical transformations in the atmosphere. Jacobson found that E85 . . ."

Admittedly, I have NOT seen original data...BUT, even though the predicted
"risk" is small...this model claims 200 more respiratory deaths per year if
the USA goes to ethanol blends at all gasoline pumps...just something to
think about that I don't remember Mr. Gore telling us !!!!!

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Tom F&L GoR

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Robbie: The StarBrite article correctly points out the problems that may arise with use of ethanol, but the magic additive isn't so magic. In fact, they double-talk themselves by saying that over a period of time, even large amounts of water will be removed. That would happen (assuming the fresh fuel has no water, too) whether the StarBrite product was there or not.

Another StarBrite document says their enzymes modify how gasoline burns, changing the bonding structure of the hydrocarbon molecules, fuel economy up 15% and more.
http://www.starbrite.com/whatsnew/2004 BoatUS Ad (Startron).PDF
The combination of claims ought to draw FTC attention.

Steve, no disagreement with the air quality results, but there is one unspoken reason. Cars today are made with gasoline in mind, so the catalyst and fuel map (and compression ratio) are designed to use gasoline (or E10) and meet gasoline emissions requirements. E85 combustion is different (partially burned alcohols, reactions of alcohol with nitrogen, etc) and I don't think E85 capable vehicles were specifically designed for those emissions. In other words, does the government have an E85 emissions test? Once E85 becomes a viable fuel, and catalysts and fuelling strategies are re-tuned, the "poor emissions" issue goes away.
 

Steve-Indy

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Thanks, Tom...I was really only trying to point out that there are always risks to every presumed benefit. Also, it is risky to read too much into any "scientific " article without seeing the whole thing...and their methods, author "affiliations", etc.

As an aside, I just finished AM coffee with our racer bunch...interesting to note how one fellow's recent conversion to non-ethanol regular gas MARKEDLY improved his fuel mielage...as you would expect.
 

Racer Robbie

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Robbie: The StarBrite article correctly points out the problems that may arise with use of ethanol, but the magic additive isn't so magic. In fact, they double-talk themselves by saying that over a period of time, even large amounts of water will be removed. That would happen (assuming the fresh fuel has no water, too) whether the StarBrite product was there or not.

Another StarBrite document says their enzymes modify how gasoline burns, changing the bonding structure of the hydrocarbon molecules, fuel economy up 15% and more.
http://www.starbrite.com/whatsnew/2004 BoatUS Ad (Startron).PDF
The combination of claims ought to draw FTC attention.

Steve, no disagreement with the air quality results, but there is one unspoken reason. Cars today are made with gasoline in mind, so the catalyst and fuel map (and compression ratio) are designed to use gasoline (or E10) and meet gasoline emissions requirements. E85 combustion is different (partially burned alcohols, reactions of alcohol with nitrogen, etc) and I don't think E85 capable vehicles were specifically designed for those emissions. In other words, does the government have an E85 emissions test? Once E85 becomes a viable fuel, and catalysts and fuelling strategies are re-tuned, the "poor emissions" issue goes away.

Tom,

I agree with you completely that Starbrite has a lot of double talk in their article. I used their product lat summer in a brand new outboard with a new built in fuel tank. I pulled the sender to make sure the tank was clean before adding Starbrite and E10 premium fuel. I bought only Mobil gasoline from the same gas station all summer. At the end of the summer I pulled the sender again and found particles that were both light brown and black. They seemed to be attracted to each other when I tried to pick them up on a wooded stick. With Starbrite there was zero improvement in the running or starting of the outboard, therefor I felt that Starbrite was junk. I will be going back to ValvTect Octane Performance Booster which I have run for years with great results and no particles left in the fuel tank.

Robbie
 
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