What is the TRUTH regarding ethanol free gasoline?

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So many opinions. Ranging from better fuel economy to worse fuel economy to better horsepower to lousier burning characteristics to farmer hating statements. What is the bottomline truth behind it? Is ethanol free broken down into 87, 89, 91 octane? I only saw "ethanol free gas" equivalent to the price of SUL here in SC.
 
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The only possible way ethanol free gasoline will give you worse gas mileage is if your car needs Premium 91 octane and you fill it with Regular 87 E0.
 
A gallon of gasoline contains ~114,000 BTUs of energy, while a gallon of ethanol contains ~76,000. Therefore, under typical conditions, operating with an ethanol blend will result in reduced fuel economy. How much depends on the blend, the driver, the vehicle, etc.

Regarding power, adding ethanol to gasoline typically raises the octane (see the 100+ octane of E85 as an example). The higher the octane number, the more resistant the fuel is to detonation (knocking). Higher compression ratios can increase power, but increase the risk of detonation. This is why performance vehicles often recommend the use of high performance fuel. If the engine is designed with high compression in mind, ethanol-blended fuels may increase performance if the octane rating is higher than comparable "straight" gasoline.

Ethanol can be harmful to fuel system components not designed for it, especially in higher concentrations.

Some engines simply "don't like" ethanol blended fuels. My 2001 Honda, for example, gets roughly 10-15% worse fuel economy with E10, regardless of octane, compared to straight 87 octane gasoline.

Run five to ten tankfuls of E0 and E10 through your vehicles and keep detailed records of price paid and observed fuel economy. Then decide if ethanol "makes cents" for you.



I doubt you will find "truth" about the economics and politics behind ethanol as all sides of that controversy will be biased. Numbers can lie, especially if it is a lie by omission.
 
Originally Posted By: strat81
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Regarding power, adding ethanol to gasoline typically raises the octane (see the 100+ octane of E85 as an example). The higher the octane number, the more resistant the fuel is to detonation (knocking). Higher compression ratios can increase power, but increase the risk of detonation. This is why performance vehicles often recommend the use of high performance fuel. If the engine is designed with high compression in mind, ethanol-blended fuels may increase performance if the octane rating is higher than comparable "straight" gasoline.

...

I agree, but I don't want someone to think that E10 at the 87 pump will have a higher octane than E0 at the 87 pump.
I suspect that ethanol is added to gasoline with octane lower than desired, so the ethanol brings it up to specification.
 
Certainly with a flex-fuel designed engine, the extremely high octane rating means that the timing can be advanced a bunch. As a result, there can be higher efficiency w/ respect to the actual energy content of the fuel. It was noted that ethanol has about 2/3 the energy content of a typical base gasoline. Also - gasoline has a certain range in terms of fuel content depending on the particular mixture.

So there are no easy answers.
 
E10 offers less power than comparable E0 Gasoline. It also offers lower fuel economy. Some vehicles are more sensitive to it than others. Another problem is Ethanol is hygroscopic(binds to water) thus wreaking havoc on fuel pumps, injectors, and metal fuel lines. It also doesn't store as well as E0 gas, that's why OPE and marine engines don't do as well on it.

As for the politics of it, that's a whole other ball of wax not worthy of BITOG.
 
Originally Posted By: strat81
A gallon of gasoline contains ~114,000 BTUs of energy, while a gallon of ethanol contains ~76,000. Therefore, under typical conditions, operating with an ethanol blend will result in reduced fuel economy. How much depends on the blend, the driver, the vehicle, etc.


I don't think what you said there can is totally correct. You just can't base it on BTUs on combustion. There are many other factors to consider than just heats of combustion.
 
Ethanol is an octane booster as it has an octane number of about 113. The issue with octane people have is it's ability to ruin engine hoses and gaskets relating to the fuel system as ethanol is hydrophilic (water liking). I have heard some controversy wrt this and I am unsure if it is true or not. I know a small engine guy that says with ethanol in gas and small engines not being built like they used too (made in China) things are just rotting away.
 
Originally Posted By: KevGuy
Originally Posted By: strat81
A gallon of gasoline contains ~114,000 BTUs of energy, while a gallon of ethanol contains ~76,000. Therefore, under typical conditions, operating with an ethanol blend will result in reduced fuel economy. How much depends on the blend, the driver, the vehicle, etc.


I don't think what you said there can is totally correct. You just can't base it on BTUs on combustion. There are many other factors to consider than just heats of combustion.


I think he's right(strat81), the BTU rating is equivalent to energy content.
 
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85 octane gas is blended with 10% ethanol to get 87 no lead E10...

Most cars run slightly rich to light off the cat, and lower emissions.
E10 or a slightly lower energy content gas will not be noticeable.

I just stopped by the Atlantic Energy station just before the Coleman Bridge in Virginia.
Ethanol free $4.03
Lots of people filling cans up...
E10, $3.25
And E85, only one around here.

I put 4.5 gallons of E85 in my tank, at $2.99 a gallon
It holds 12 gallons.
Your average car can burn 24% Ethanol no problem, mine can run 40%.
No mileage drop noticeable...

Small engines, I try and run Ethanol free...
 
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Yes ethanol has less energy than gasoline however considering there's only 10% ethanol in fuel the difference in mileage between the 2 fuels wouldn't be measurable

Here in sask regular has 10% ethanol and premium has none,and mid- grade is mixed at the pump which makes it 5% ethanol.


I have tested both regular vs premium in my charger it's noticeably more responsive and gets a minimum of 4mpg better with premium fuel.
It should be noted that I've tuned the car with a diablosport tuner,and timing has been advanced.

The c3 seems to gain 2 mpg on the highway based on what I've seen so far.

My girls windstar doesn't run any different,nor gain any mileage when using premium fuel vs regular ethanol treated fuel.
I doubt very much that fuels of the same octane,and the only variable that's different is 10% ethanol,I doubt that there would be any measurable difference in fuel economy
 
Originally Posted By: 29662
E10 offers less power than comparable E0 Gasoline.

Do you have a source for that claim? I understand the other potential issues, but I've never heard that less power will be produced. It would produce just as much power by dumping a higher volume of fuel. I've even read that in certain carb applications where the jets are increased in size, E10 can actually increase power because it overcomes the air restrictions by getting more oxygen in the combustion chamber.

Flex fuel cars running on E85 are known to have increased performance, but that's a matter of advancing the timing.
 
Originally Posted By: KevGuy
Ethanol is an octane booster as it has an octane number of about 113. The issue with octane people have is it's ability to ruin engine hoses and gaskets relating to the fuel system as ethanol is hydrophilic (water liking).

Are you equating octane rating with octane content? It's not boosting the actual amount of octane. It's improving the antiknock properties relative to a reference fuel of iso-octane and n-heptane.

There are no issues with hose/seal compatibility with any car made in the last couple of decades. They all use components exposed to the fuel that were designed with ethanol fuels in mind. I remember hearing about classic cars that had issues with E10, but often these went away when their seals and hoses were replaced with modern ones.
 
Originally Posted By: y_p_w
Do you have a source for that claim? I understand the other potential issues, but I've never heard that less power will be produced.

I'm assuming the claim refers to energy density. Of course, a higher volume of fuel would help "balance" the matter. The claim of energy density also is separate from combustion efficiency.
 
This is what I know for a fact. We take the wife's 2012 Equinox 2.4 when we visit Tulsa OK where my daughter lives. I get 2.5/MPG better mileage going back with E0 in tank. This is figured by the ECU and my miles driven/gallons gas used "rith-ma-tic", we come up with almost the same figures. Same road, same speeds same everything.
I put E85 in once, didn't run any better, and lost over 6 MPG city/4 MPG highway. This was two full tanks to get honest figures.
Gasoline is for use in cars/trucks.
Ethanol is for.......well, making Ethanol plants money. Remember, Gov "still" subsidizing Ethanol with "our" tax dollars. Why if its so good???
You really want to use Ethanol? Make engines Ethanol ONLY. At least 13 to 1 compression with E95 blend. It might work then...but I doubt they could produce enough of it then for sea to sea USA consumption.
My 2 cents on this "E" story.
 
I ll speak for my view.the main issue with ethanol is its love for water.and the fact it is very harsh on engine part.if you are at 1% or 2% level you are fine.its probably even beneficial.but at 10% or more?it isnt good long term.
 
Originally Posted By: oldhp
Ethanol is for.......well, making Ethanol plants money. Remember, Gov "still" subsidizing Ethanol with "our" tax dollars. Why if its so good???
You really want to use Ethanol? Make engines Ethanol ONLY. At least 13 to 1 compression with E95 blend. It might work then...but I doubt they could produce enough of it then for sea to sea USA consumption.
My 2 cents on this "E" story.

One issue these days is the larger proportion of engines designed for premium. 92 octane premium used to be the predominant number on premium fuel pumps in California, but it's been 91 since about 2000. It was a matter of meeting the demand for premium without having to find some use for lower octane fuel streams.

Some sort of oxygenate that boosts the octane rating is important. Even if it wasn't subsidized, there would be a need for oxygenates. We can't use TEL any more. They've already maxed out the ability of make higher octane rating base fuel through cracking. MTBE is no longer used; I understand it's not illegal but no oil company would touch it.
 
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