ETHONAL BAD
5th Gear Member
Joined: Oct 2006
Posts: 3,115
From: Baytown, TX
RE: ETHONAL BAD
its not that is less combustable but that it has more energy (chemical potential) and needs more energy to ignite but also releases more
http://www.prime-mover.org/Engines/G...es/octane.html
so by needing more energy to ignite it prevents preignition more
also the way the gas comps change octane usualy involves mixing a verious hydrocarbons (to low and they add a heavier hydocarbon)
for instance the way they boosted oct in the old days was lead it was cheap and easy but didn't really add energy
have you ever burned candle wax (not by wick but actualy the wax its self on fire without a wick)
now wax has alot more chemical potential than gas so it takes a lot of energy to really ignite and gives off alot of energy (enough to crack glass with pure heat)
http://www.prime-mover.org/Engines/G...es/octane.html
so by needing more energy to ignite it prevents preignition more
also the way the gas comps change octane usualy involves mixing a verious hydrocarbons (to low and they add a heavier hydocarbon)
for instance the way they boosted oct in the old days was lead it was cheap and easy but didn't really add energy
have you ever burned candle wax (not by wick but actualy the wax its self on fire without a wick)
now wax has alot more chemical potential than gas so it takes a lot of energy to really ignite and gives off alot of energy (enough to crack glass with pure heat)
3rd Gear Member
Joined: Apr 2006
Posts: 632
From: Charlotte NC
RE: ETHONAL BAD
Actually, the 15% alcohol that you are talking about is what used to be referred to "gasohol."
Up to 15% is safe for your engine. Over that and certain parts of your fuel system (specifically butyl rubber, but also some coatings, such as fuel tanks in older cars) will deterioriate.
Alcohol actually has LESS energy than gasoline. That is the reason that the stochiometric formula is 14.7 parts of air to one part gas for gas and roughly10.5 (depending on methanol or ethanol) parts air for 1 part of alcohol. Race cars use it for it higher inherent octane (can build a motor with higher static compression ratio) and greater charge cooling given the higher consumption of fuel.
I does have the downside of increased engine wear and increased absorption of water vapor.
Up to 15% is safe for your engine. Over that and certain parts of your fuel system (specifically butyl rubber, but also some coatings, such as fuel tanks in older cars) will deterioriate.
Alcohol actually has LESS energy than gasoline. That is the reason that the stochiometric formula is 14.7 parts of air to one part gas for gas and roughly10.5 (depending on methanol or ethanol) parts air for 1 part of alcohol. Race cars use it for it higher inherent octane (can build a motor with higher static compression ratio) and greater charge cooling given the higher consumption of fuel.
I does have the downside of increased engine wear and increased absorption of water vapor.
3rd Gear Member
Joined: May 2007
Posts: 550
From: DE
RE: ETHONAL BAD
All gas in the US has Ethanol in it at 15% for anything that is not E85. Ethanol replaced the other additive (MTPT sp) that congress outlawed due to it can cause cancer and was getting into the water tables.
As for gas in general. You do know that the gas you buy at your local gas stations, any gas stations, are refined in the same refinery. Gasoline is shipped in the country via pipe lines. In Delaware it is all refined at the Valero Refinery in Delaware City. The local companies simply put additives in the gas after it has been placed in the tanker truck that delivers to the stations. The Discovery Channel or History Channel has a story on gasoline. I think it was one of the Modern Marvels shows. All gas is pretty much the same, major differences are octane ratings, and location in the country. North East America has a "cleaner" burning gas then say the Midwest.
Just buy the gas based on price. You will always have a chance to get so "bad" gasoline.
As for gas in general. You do know that the gas you buy at your local gas stations, any gas stations, are refined in the same refinery. Gasoline is shipped in the country via pipe lines. In Delaware it is all refined at the Valero Refinery in Delaware City. The local companies simply put additives in the gas after it has been placed in the tanker truck that delivers to the stations. The Discovery Channel or History Channel has a story on gasoline. I think it was one of the Modern Marvels shows. All gas is pretty much the same, major differences are octane ratings, and location in the country. North East America has a "cleaner" burning gas then say the Midwest.
Just buy the gas based on price. You will always have a chance to get so "bad" gasoline.
4th Gear Member
Joined: Aug 2006
Posts: 1,007
From: TX
RE: ETHONAL BAD
+1
ORIGINAL: Leoleo
All gas in the US has Ethanol in it at 15% for anything that is not E85. Ethanol replaced the other additive (MTPT sp) that congress outlawed due to it can cause cancer and was getting into the water tables.
As for gas in general. You do know that the gas you buy at your local gas stations, any gas stations, are refined in the same refinery. Gasoline is shipped in the country via pipe lines. In Delaware it is all refined at the Valero Refinery in Delaware City. The local companies simply put additives in the gas after it has been placed in the tanker truck that delivers to the stations. The Discovery Channel or History Channel has a story on gasoline. I think it was one of the Modern Marvels shows. All gas is pretty much the same, major differences are octane ratings, and location in the country. North East America has a "cleaner" burning gas then say the Midwest.
Just buy the gas based on price. You will always have a chance to get so "bad" gasoline.
All gas in the US has Ethanol in it at 15% for anything that is not E85. Ethanol replaced the other additive (MTPT sp) that congress outlawed due to it can cause cancer and was getting into the water tables.
As for gas in general. You do know that the gas you buy at your local gas stations, any gas stations, are refined in the same refinery. Gasoline is shipped in the country via pipe lines. In Delaware it is all refined at the Valero Refinery in Delaware City. The local companies simply put additives in the gas after it has been placed in the tanker truck that delivers to the stations. The Discovery Channel or History Channel has a story on gasoline. I think it was one of the Modern Marvels shows. All gas is pretty much the same, major differences are octane ratings, and location in the country. North East America has a "cleaner" burning gas then say the Midwest.
Just buy the gas based on price. You will always have a chance to get so "bad" gasoline.
4th Gear Member
Joined: Aug 2006
Posts: 1,007
From: TX
RE: ETHONAL BAD
I think what he's was trying to say was the E15 gas everyone uses is not made by mixing E85 to our gas. Its made by mixing E100 to normal gas to create the E15. so the put 85% gas and 15% Ethanol together to make our gas.
ORIGINAL: Sleeper05
No chit. What you failed to read into is that I was referring to HOW MUCH of the volume of the gas was actually e85. That number would be *up to* 15% depending on the state.
ORIGINAL: TxLonghorn
Actually, e85 would be 85% ethanol. If its 15%, then its E15, so in that case, E85 would be dangerous to your engine. [8D]
ORIGINAL: Sleeper05
e85 ethanol is not dangerous to your motor. It will only be mixed up to about 15% by volume. The simple fact that it is potentially in there will NOT affect the octane rating, because the mixture will still have a minimal rating of 87.
e85 ethanol is not dangerous to your motor. It will only be mixed up to about 15% by volume. The simple fact that it is potentially in there will NOT affect the octane rating, because the mixture will still have a minimal rating of 87.