With gas prices crossing $4 a gallon, the EPA says cheaper, more ethanol-rich fuel will ease the pain. The math doesn't really add up—but the risks sure do.
If i remember correctly, from way back in college chemistry, i learned E85 is already partially oxidized. So you are getting less energy out of the fuel. It’s a step backward, and definitely isn’t going to make anything better.
I don’t know the specific reasons, but yes, ethanol is less energy dense. The communities talking about this factually see that the loss in MPGs is pretty close to the average price difference, making it a net zero benefit.
You said “if I remember correctly”. Since ethanol isn’t the same compound as as those found in gasoline, I’m not going to rely on an “if I remember correctly” statement about the specifics when there’s verifiable proof on the road that, regardless of cause, it’s lower. I was confirming your overall claim and agreeing with you.
So anyway, since now I’m driven to look up the specifics, yes, being partially oxidized is part of the problem, but that by itself is not the complete problem. With different compounds it wouldn’t even be relevant. There are gasoline compounds that carry oxygen. C2H5OH (ethanol) is a relatively small molecule compared to the hydrocarbons in gasoline mixtures. Even if it didn’t have that one oxygen atom, it’d still have fewer hydrogens to use than the main components of gasoline. And those gasoline compounds can be arbitrarily longer than their minimum molecule designation.
It’s the single oxygen atom and the fewer total number of hydrogens, combined.
If i remember correctly, from way back in college chemistry, i learned E85 is already partially oxidized. So you are getting less energy out of the fuel. It’s a step backward, and definitely isn’t going to make anything better.
I don’t know the specific reasons, but yes, ethanol is less energy dense. The communities talking about this factually see that the loss in MPGs is pretty close to the average price difference, making it a net zero benefit.
I just gave you the reason, it’s already partially burned. That’s what partially oxidized means.
You said “if I remember correctly”. Since ethanol isn’t the same compound as as those found in gasoline, I’m not going to rely on an “if I remember correctly” statement about the specifics when there’s verifiable proof on the road that, regardless of cause, it’s lower. I was confirming your overall claim and agreeing with you.
So anyway, since now I’m driven to look up the specifics, yes, being partially oxidized is part of the problem, but that by itself is not the complete problem. With different compounds it wouldn’t even be relevant. There are gasoline compounds that carry oxygen. C2H5OH (ethanol) is a relatively small molecule compared to the hydrocarbons in gasoline mixtures. Even if it didn’t have that one oxygen atom, it’d still have fewer hydrogens to use than the main components of gasoline. And those gasoline compounds can be arbitrarily longer than their minimum molecule designation.
It’s the single oxygen atom and the fewer total number of hydrogens, combined.