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Discussion Starter · #1 ·
Last night I tried an experiment with ethanol usage in a Prius. I used a 36% ethanol/64% gasoline mix, and drove a round trip of 120 miles. No problems overall. There was a perceptible increase in power and a 9% decrease in gas mileage.

Details:

The Prius is designed to use up to a 10% ethanol/90% gas mix. This is needed for operation in some states that use ethanol as an oxygenate instead of MTBE. From this I concluded that the Prius fuel system had been designed to accomodate some amount of ethanol without degradation, and the surfaces in the catalytic converters would not be degraded by combustion products involving small amounts of ethanol.

Then I took a look around the web, and found a study done by Minnesota State University where they ran a Prius on E85 (85% ethanol, 15% gas) and measured emissions results. They discovered a reduction in three pollutants (HC, NOx, and CO) an increase in power of 20% and a reduction in overall gas mileage. They also discovered that after approx 140 miles they would get a check engine light. They used a diagnostic tool to check the error code; apparently the error was due to the computer having to increase the richness of the mixture by 32% to deal with the added oxygenate in the fuel. The computer did not have a problem making this adjustment but did set an error code since it was outside its expected range. See link below for more information.

I thought that perhaps a less aggressive mix of ethanol and gasoline would bring some of the benefits of ethanol operation (i.e. decreased reliance on petroleum, increased power) without setting the error light. A 36% mix would only require a 14% mixture adjustment; this might be within the 'legal' range of the mixture adjustment.

To get the right mix I filled several 5 gallon cans with E85 from a local gas station. (They made me sign a waiver saying I wouldn't sue them if I damaged my vehicle, which I thought was funny.) E85 cost was $2.10 a gallon; local gas costs around $2.50 a gallon. I filled the Prius from one of the cans and topped it off with regular (87 octane) gas from a local gas station. Calculating the amounts got me a 36% ethanol mix.

I then drove a 120 mile round trip with one passenger. No error lights, and my mileage, as determined by the car's computer, dropped off by about 9% while giving me a noticeable increase in power. This leads to a fuel cost of 5.4 cents per mile with normal gas and 5.6 cents per mile with the E36 mixture I used.

So overall a bit of a pain to mix the fuel manually, but it seemed to work well. I may try a mixture up to 50% ethanol next.

Link to study:
http://66.102.7.104/search?q=cache:...rid%20report.doc+ethanol+prius+test+E85&hl=en
 

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Talk about possibly voiding a warranty... :roll:

Not to mention that ethanol is SO heavily subsidized that it's deceptively inexpensive. Yes, I know US gas is, too. It takes far more energy to make ethanol that the end user gets out of it. Chances are good that the use of ethanol is more polluting in the long run (energy to produce, lower miles per gallon leading to the use of more of it than gas for comparable miles traveled). Dunno, but I am not convinced ethanol is the way to go.
 

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Gee, I totally misread that article the first time, or I read a copy of it elsewhere. I thought I had read that ethanol had LESS power.



Problem is, no longterm study was done, so you could be eating rubber and plastic a little at a time.
 

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How can you mix pure gasoline (0% ethanol) and E85 (15%) ethanol, and end up with MORE than 15% ethanol? You claim to get 36% ethanol.

Maybe we've discovered the ethanol equivalent of cold fusion here!
 

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Discussion Starter · #5 ·
DanMan32 said:
Gee, I totally misread that article the first time, or I read a copy of it elsewhere. I thought I had read that ethanol had LESS power.

Problem is, no longterm study was done, so you could be eating rubber and plastic a little at a time.
True. There is certainly some inherent resistance to ethanol since the fuel system is designed for up to 10% ethanol, but a normally very slow degradation could be accelerated by the higher concentrations.

KTPhil said:
How can you mix pure gasoline (0% ethanol) and E85 (15%) ethanol, and end up with MORE than 15% ethanol. You claim to get 36% ethanol.
E85 is from 70-85% ethanol depending on formulation.
 

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Oh!

I had thought it was the other way around--E85 was 85% GAS. We have about 10% ethanol as a substitute for MTBE so I thought E85 qas just a bit richer in ethanol. Nope, apparently!
 

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So once you drive 20 more miles you should get the check engine light, right? (140 miles driven by Univ. to get light - 120 driven by billvon = 20 to go). But maybe you have to drive 140 * (85/36) = 331 miles to get the light, so 211 miles to go.
 

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KTPhil said:
Oh!

I had thought it was the other way around--E85 was 85% GAS. We have about 10% ethanol as a substitute for MTBE so I thought E85 qas just a bit richer in ethanol. Nope, apparently!
It IS richer in ethanol.

E10: 90% gasoline, 10% ethanol
E85: 15% gasoline, 85% ethanol. This is richer (more) in ethanol.
 

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I would have thought that if you are getting more power, you would be using LESS fuel, therefore higher MPG. More energy per gallon.

Then again, maybe I misread your initial post, and that IS what you said.
 

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Discussion Starter · #11 ·
DanMan32 said:
I would have thought that if you are getting more power, you would be using LESS fuel, therefore higher MPG. More energy per gallon.
As I understand it -

Alcohol has less chemical energy than gasoline, so you need more to get the same energy. However, it contains a significant amount of oxygen; hence its use as a fuel oxygenate. A modern car compensates for this by increasing the amount of fuel injected into the cylinder, so stochiometric combustion is maintained. Since there is more fuel per stroke, the engine can generate more power overall, but at the expense of fuel economy.
 

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Sanny said:
Talk about possibly voiding a warranty... :roll:

Not to mention that ethanol is SO heavily subsidized that it's deceptively inexpensive. Yes, I know US gas is, too. It takes far more energy to make ethanol that the end user gets out of it.
Kind of. Most of the operations are small and therefore don't use the energy to make it as efficiently as the huge refineries. Also it takes a much longer time and the distribution system isn't as efficient. But.... like battery technology, the technology to create ethanol is changing, quite rapidly. The interesting thing is its potential as a hydrogen source for fuel cells. Again the question is, is it in our best interest to pursue increased production which therefore increases R & D?
 

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I think so. First off, latest studies show it does provide slightly more energy than it takes to produce. With increase in technology, the net output could be increased.

However, unlike hydrogen, we can use ethanol in existing sytems and methods of distribution with minimal modification.
 

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A lot of the energy for ethanol is used it the growing of the corn, it takes a lot of corn to make ethanol. Ethanol is politically popular (farmers love it), receives lots of corn subsudies, is a "quick fix" (read - easy) and will get more expensive as use increases. We can't grow corn fast enough for this to be a primary fuel.
 

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Discussion Starter · #15 ·
Update:

So far I've run five tanks of ethanol/gas mix in my 05 Prius with no problems. Mixtures have ranged from 30% to 50% ethanol. Average MPG drops about 10% with these mixes. Power seems increased although I can't quantify that.
 

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Sanny said:
Not to mention that ethanol is SO heavily subsidized that it's deceptively inexpensive. Yes, I know US gas is, too. It takes far more energy to make ethanol that the end user gets out of it. Dunno, but I am not convinced ethanol is the way to go.
I agree and disagree with you on this one. While Ethanol and gas (and corn) are currently subsidized, Ethanol is not more expensive in the long run. Really... the argument stems around "Expensive."

Depending how you look at it, Ethanol can be made from Corn in mass quantities. But it really has not really been properly researched in the US. So current Ethanol prices are far more then if the US implemented large Ethanol facilities. Other power sources other then petroleum could be used to make Ethanol. Brazil too about 20 years to make themselves almost 100% self-sufficient by using Ethanol and weening themselves from foreign oil. However, Brazil is going from sugar to ethanol not corn. The part about Ethanol using more energy to create then gas is also extremely biases because you don't consider that 1 million years of decomposition that it takes to "make" oil. So, from Corn Seed to Ethanol is unfairly comparison from then Oil to Gasoline. Corn to Ethanol should be compared to Dinosaur to Gasoline. :) Plus... oil has many other factors to include. Shipping, impact to nature (spills), not to mention the added cost of gas if we need to have wars to secure supply. Gas is a limited supply so its a supply and demand commodity, unlike a ethanol which we can adjust the supply. Ethanol can be produced in the US from Corn and as the country has a problem limiting its fuel consumption use we might as well also aid our poor farms. We have already put off Ethanol research and mass production long enough and now billions of dollars are spent securing oil instead of researching alternate fuels. Researchers believe that 1/10 of the budget of the current war could have solved the ethanol problem had the money been placed in research. And that doesn't even factor in the value of human life. Even if we didn't come up with a solution the money would have been better spent then killing people. You would have a bunch of nerds feeling dumb rather then thousands of lives torn apart from war.

Now... all things considered... going from Sun > Corn > Ethanol > Hybrid (Ethanol/Electricity) seems retarded then going from Sun > Electricity. As every conversion of energy has loss. But... current solar cells need petroleum and power to make cells.

In the end I think the money has to be removed as money has no environmental value. In the end a Billion dollars won't mean a thing in a world full of Green House gases and no fossil fuels. We need to stop looking at the short term and not the long term. I think Ethanol research would be a good short term research solution until better re-new-able energy solutions can be invented.

Of course... conservation would fix all the problems too... hmmm...

Well... we now have a 1 car family so we are doing our part.

In the end you can not do anything without using energy, it just choosing what energy you use to do it. Re-new-able energies are far better in the long run especially when it comes to a stable economy.

In the end... I could care less if we used Bio-Diesel, Ethanol, or Hydrogen... just something other then diesel. What ever we choose it's better then gas and in 50 years we will look back and say WTF do we do that for because something better will come around... but using gas is as archaic now as coal was in the 1920's.

I think the reason the US government will always say that the war is not for oil is because admitting it would mean that all gas using US citizens are in part responsible for the lives lost in the war... which is the trueth... even us hybrid drivers.

-Hays
 

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gschoen said:
A lot of the energy for ethanol is used it the growing of the corn, it takes a lot of corn to make ethanol. Ethanol is politically popular (farmers love it), receives lots of corn subsudies, is a "quick fix" (read - easy) and will get more expensive as use increases. We can't grow corn fast enough for this to be a primary fuel.
Not as a primary fuel, but if we used 20% ethanol mix, that's about 10% (I'm guessing here) less oil we have to buy. This keeps the money in this country, which helps the economy. We also don't have to pay farmers to not grow, which saves the government money. We can also tax the corn and products, generating more government income.

Also, there are other plants that grow faster that we can use.
 
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