E - 85

[nancejd]

If there are any physical differences in the vehicle, I would think it would be in things like o-rings on the fuel injectors, fuel ines, etc.

[68Formula]

I checked the engines on the line at work today. The Flex Fuel 5.3s use the very same oxygen sensor (between manifold and cat. con.) as the gas only 5.3 and 4.8.
After giving it some thought, I realized that the O2 sensor does not measure fuel ratio directly but does measure the amount of oxygen left in the exhaust gas. I'm thinking that if both gasoline and E85 are burnt at the correct ratio, the same amount of oxygen would be left in the exhaust. With enough injector and computer capacity, the mixture could easily be richened up/leaned out as the amount of ethanol increases/decreases in the fuel mixture. Does this make sense to anyone else?
Ken

Sounds reasonable. It's really correcting for stoich condition (the fuel type's ideal mixture for burning).

While you're down there, I've heard the catalyst (at least for 100% Ethanol) is different (read expensive). Any chance you take a look at that as well?

[Y-TRY]

So, I could/should go find some E-85 and put it in my engine ASAP?

But how in the world to find it?

[MarkM66]

Curious as to why some are referring to Ethanol and Methanol as corrosive, when a non aqueous solution will have no pH.

Look at an MSDS for either, and you'll always find n/a.

Just looked at one for E85, pH N/A.

So if something is breaking down rubber, copper etc. it's not due to corrosivity. Hygroscropic qualities perhaps?

[gwbutch]

Curious as to why some are referring to Ethanol and Methanol as corrosive, when a non aqueous solution will have no pH.

Because we live in an imperfect world where storage tanks tend to accumulate water. Yes, those tanks have drains on them, but with alcohol in the solution, water will solubilize into the hydrocarbon/alcohol solution creating a corrosive solution which will corrode stuff. The MSDS only reports the information of the alcohol, not of an alcohol/water mixture.

[MarkM66]

Because we live in an imperfect world where storage tanks tend to accumulate water. Yes, those tanks have drains on them, but with alcohol in the solution, water will solubilize into the hydrocarbon/alcohol solution creating a corrosive solution which will corrode stuff. The MSDS only reports the information of the alcohol, not of an alcohol/water mixture.

What does the water and alcohol solution turn into which makes it corrosive? Since alchohol has no pH, and Water is obviously neutral.

I think you would have to have quite a bit of contamination in this tank to turn it into a true corrosive. As in a pH <= 2, or >=12.5.

[gwbutch]

There are all kinds of acids that are developed from crude oil. Corrosion is a big problem in the top of crude distillation towers (which is where the naphtha or gasoline goes). Most of the water soluble acids drop out in the separators, but some stays in the oil phase and moves on. Alky units use an acid in their process. The alky is used in blending gasoline. We don't have an alky unit, so I'm not that knowledgable about them. The point is alcohol is a two phase chemical. It is soluble in both water and hydrocarbon. Any water that is around, ie. storage tanks, transfer lines, atmosphere, will solubilize into the gasoline. Are you familiar back in the olden days when carbs would freeze up due to water in the fuel? And you do not need a pH < 2 to cause corrosion. A pH of 6 will corrode carbon steel.

[MarkM66]

Good info.

I would imagine with a pH of only 6, it would take a long to to do any damage to a fuel system.

[Kenova]

While you're down there, I've heard the catalyst (at least for 100% Ethanol) is different (read expensive). Any chance you take a look at that as well?

The Flex Fuel 5.3, gas only 5.3s, and the 4.8 all use the same cat and crossover pipe. I'm beginning to think that using ethanol rather than methanol, and adding the 15% of gasoline solves a lot of problems when compared to 100% ethanol or methanol.
It looks like the biggest hassle with E85 is increasing your compression ratio to take advantage of it. But hey, that's easy enough to fix with some sort of bolt on forced induction.
Ken

[nancejd]

I wonder about the soft parts though. What about all of the seals on the fuel system?

[67SSDan]

Maybe some of you smart guys can comment on this. I was in a discussion with a guy about this the other day. He was saying that the "fuel value" of E85 is lower then that of regular pump gas, meaning that given the same scenarios, it would take MORE E85 to accomplish the same task as gas. Any truth to that?

His slant on it was that over the past couple of years there has been a trend of adding stuff to gas (and subsequently lowering the "fuel value") and at the same time the cost keeps going up... leaving us paying more for something of lesser value. He was pissed because the cost of E85 is supposed to be not THAT much cheaper then what we're paying now (some of you guys who can actually get the stuff please comment here), and the supposed value of it is lower as well.

Comments?

[derekf]

Dan - yes.

Check out http://www.fueleconomy.gov/feg/byfueltype.htm

A 2006 Monte Carlo gets 31mpg highway on gasoline, but only 24 on E85. The EPA at this site is actually estimating that the cost per year to run the vehicle is higher with E85 than with gasoline.

[andrewb70]

For what its worth, I just called a local supplier of E85 and it was $2.14 per gallon.

Andrew

[68Formula]

What's race gas run these days? Gotta be at least $3.50/gallon by now.

Problem with flex-fuel cars is they're compromised to run both. I'm sure the fuel economy would improve a little if you could bump the compression a couple points to take advantage of the octane.

[Fuelie Fan]

Is that a funny? Where I am, 91 is $3.50/gallon

Ethanol has a much lower stoichiometric point, I beleive it's around 9:1. So, if you're at stoich to please the catalyst, you are going to burn more fuel. E85 is around 10:1. So, in order for E85 to save us money, it would have to be 2/3 the cost or less.

Ethanol also has a lower HHV, but when you combine it with how much richer the mixture is, the HHV x volume of fuel burned gives you more total energy. Same with Methanol. So, "in theory" you can make slightly more power with it even before you start optimizing the engine by raising compression.

[MarkM66]

I think Stoich for E-85 is 9:1, as opposed to 14.7:1 like normal gas. Figures may be slightly off.

It was in a tech question in the latest Hot Rod.

[Fuelie Fan]

http://www.eere.energy.gov/afdc/pdfs/fueltable.pdf

Pure ethanol is in fact 9:1, which would make E85 closer to 10:1

[nancejd]

So assuming that E-85 gets you 2/3 as far as regular gas at $2.14 a gollon, regular would have to be $3.21 a gallon to break even. Not to mention that if you can run a higher compression ratio with E-85, that means it should be a good substitute for super unleaded, which looking out my window here at work at the Safeway across the street is at $3.37 a gallon. I've seen regular at $3.31 a gallon locally at the highway stores.

Sounds like a pretty good deal to me, I'd take the reduced range and fill up more often. Plus, I would bet that the cost of E-85 would drop as the supply increases due to demand, and more manufacturing and distribution comes on line.

[ItsA68]

the best thing about the E85 is that we don't have to buy 85% of it from someone that would just as soon kill us all. now if the govt would stop propping up the price of corn, stop paying farmers NOT to grow it, and maybe that E85 would be even less expensive to produce. future will be celulose type fermentations for Ethanol from what I see.

~~fred

[Kenova]

Can you make ethanol from garbage? There is no shortage of the stuff, and it would be nice to get a little something extra from it before it hits the land fill or incinerator.
Ken