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Old 03-31-2013, 09:59 PM   #1
Charlton
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Default Straight Gas vs Gas with Ethanol

We've got a couple gas stations with 100% gasoline here locally. Would there be a benefit doing straight gas vs gas with ethanol?
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Old 03-31-2013, 10:06 PM   #2
97cv
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I So Envy You!
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Old 03-31-2013, 11:21 PM   #3
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Straight gas has better gas mileage. That's really about it.

Ethanol slightly increases knock resistance.
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Old 04-01-2013, 12:16 AM   #4
RaceFaceXC
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Quote:
Originally Posted by formula91 View Post
Straight gas has better gas mileage. That's really about it.

Ethanol slightly increases knock resistance.
Ethanol has less energy per mass compared to gasoline, hence the slight loss of mpg's with an ethanol blend. The knock resistance gained with ethanol is lost when blended with gasoline at such a low percentage. I assume the gasoline is just a slightly lower octane rating then it used to be and then it's boosted back up to the posted octane number when the ethanol is added. That would make sense for the oil companies.

Ethanol is also not inert when in contact with many types of plastics and rubbers. It's harder on some parts of the fuel system.
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Old 04-03-2013, 02:19 PM   #5
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Originally Posted by RaceFaceXC View Post
Ethanol has less energy per mass compared to gasoline, hence the slight loss of mpg's with an ethanol blend. The knock resistance gained with ethanol is lost when blended with gasoline at such a low percentage. I assume the gasoline is just a slightly lower octane rating then it used to be and then it's boosted back up to the posted octane number when the ethanol is added. That would make sense for the oil companies.

Ethanol is also not inert when in contact with many types of plastics and rubbers. It's harder on some parts of the fuel system.

Less energy per pound but more pounds per gallon. You have to factor density of ethanol in there too. You will have more energy than if you just calculate percentages. One gallon of gasoline weighs 6# and one gallon of pure ethanol weighs 7#.

Ethanol doesnt show knock resistance well on a octane test. Reason for this is because you start with super hot manifold air and on a real engine the ethanol would greatly lower intake air temps. Pure ethanol has a octane rating of less than 100 but can easily replace 110 octane gasoline because of this reason. So even at 10% mixed with 87 you would still have more than what the R+M/2 would suggest.

My 95 impreza is rated for gasohol up to 10%. Everything since the mid 80s is ethanol compatible. My state has used ethanol in the gas for a long time and people are now only demonizing it because the media and the uninformed are blaming ethanol. There are many other much more agressive solvents in common gasoline blends that can cause problems. Blame the EPA not ethanol.
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Old 04-03-2013, 07:52 PM   #6
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straight gas will cause less damage to your fuel injectors and fuel pumps, will give you better MPG too not much through 2-5% better MPG
ethanol has 20% less BTUs per gallon than gas and gas generally uses 10% ethanol here.

Ethanol is a scam to make monsanto rich off of their overpriced GMO corn seed
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Old 04-04-2013, 05:56 AM   #7
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Originally Posted by stevefazek View Post
straight gas will cause less damage to your fuel injectors and fuel pumps,
Proof??
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Old 04-04-2013, 07:15 AM   #8
AWDmonk
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Let me go ahead and sum up 15 years of personal driving experience along with millions more around the world.......

**** E10.
**** E20...if you don't know, you're lucky.
E85, well, no turbo so no opinion.

91/93 octane in WI are 100% gas and I get 1-2 more MPG on that than on 87. The price difference made me reconsider when I was young and underemployed, but now that its ****ing $4/gallon anyway, another quarter doesn't matter.

Also, ethanol is corrosive to the seals in the fuel system. Actually, we store 100k+ pounds of E99 at work and have just recently switched to plastic tanks because it was starting to eat at the steel ones.
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Old 04-04-2013, 03:14 PM   #9
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Originally Posted by kay95 View Post
Less energy per pound but more pounds per gallon. You have to factor density of ethanol in there too. You will have more energy than if you just calculate percentages. One gallon of gasoline weighs 6# and one gallon of pure ethanol weighs 7#.
Last time I checked I purchased fuel in Gallons, so essentially you are getting less BTU (power) per gallon.

Quote:
Originally Posted by kay95 View Post
Ethanol doesnt show knock resistance well on a octane test. Reason for this is because you start with super hot manifold air and on a real engine the ethanol would greatly lower intake air temps. Pure ethanol has a octane rating of less than 100 but can easily replace 110 octane gasoline because of this reason. So even at 10% mixed with 87 you would still have more than what the R+M/2 would suggest.
One of the few redeeming qualities...

Quote:
Originally Posted by kay95 View Post
people are now only demonizing it because the media and the uninformed are blaming ethanol. There are many other much more aggressive solvents in common gasoline blends that can cause problems. Blame the EPA not ethanol.
Aside from the obvious less power per gallon, ethanol is corrosive and this isn't "media hype" Underwriters Laboratories (UL) for the National Renewable Energy Laboratory (NREL) have both confirmed this repeatedly. Ethanol is also Hygroscopic, so introduction of water into the fuel system is a concern.
On top of all of that, ethanol/gasoline combustion is actually "dirtier" than straight gasoline. The geniuses running the federal government dance around or just plain ignore this fact and choose to frame the issue by stating that the "overall production emissions" for corn are much lower than that of oil.

In summation: What comes out of your tailpipe is dirtier than the alternative, more expensive than the alternative, is more harmful to your vehicle than the alternative and this "improvement" has increased food prices worldwide.
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Old 04-04-2013, 08:50 PM   #10
chazly413
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I'd focus more on driving habits over which gas you use to improve MPGs.
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