I was wondering since 3.0 are made set to run only to reconize E85 and run it at a min. with lower gas milage as the result, would a chip and or programing the computer for the higher octance and diffrent fuel help out on the milage. I just was thinking about what i have read in prevoius post.

A little info on gasoline and ethanol:

Air-Fuel Ratio
Gasoline = 14.7:1
Ethanol = 6.5:1
E85 (Theoretical) = 8.0:1

Energy Value
Gasoline (Approx.) = 125,000 BTUs
Ethanol (Approx.) = 85,000 BTUs
E85 (Theoretical) = 90,000 BTUs

Octane Rating
Gasoline = 87,89 & 91 or 93
Ethanol = 113
E85 = 100 to 105

Changing the ignition timing alone would not make it more efficient on E85. It is possible, but just not that simple. The reason E85 is less efficient than Gasoline is because it already contains a large amount of oxygen. To create a good mixture air fuel ratio has to be much higher for E85. Another negative is that Ethanol contains less energy than Gasoline. However this is made up for by the fact that Ethanol burns slower than Gasoline. This creates a more complete burn and transfers power better to the piston. Because of this, you will actually have more power with E85 than with Gasoline.

If you do the math, using the air-fuel ratio of double that of Gasoline, you should get almost a 45% loss in fuel mileage. I don't know why its only 25%, but I can assume it is because the computer adjusts the timing as well as the air-fuel ratio. The efficiency of E85 at 9.3:1 is probably better than that of Gasoline at the same ratio also.

Optimizing an engine to run on Ethanol
A Gasoline engine can be optimized to run on Ethanol. This will create much better efficiency. By some accounts more than that of Gasoline in the same engine. Due to the much higher Octane Rating, a higher compression ratio can used on an E85 engine. The EPA used a 19.5:1 compression ratio on the test engine they built, but I have seen 14-15:1 thrown around by others. By raising the compression ratio, efficiency will be increased. Since the 3.0 only has an air fuel ratio of 9.3:1 it can not maximize the efficiency of E85. It would be the same as if the engine was built to run a compression ratio of 5.0:1 on Gasoline.

interesting info. too bad we cant get the stuff here in GA. wonder if moonshine would work? :driving: HA

Yea out here in Kentucky you could run that cheaper than anything

interesting info. too bad we cant get the stuff here in GA. wonder if moonshine would work? :driving: HA

Moonshine is the same thing as Ethanol. They are both distilled from corn. Mix 85% Moonshine w/ 15% Gasoline and it should run just the same. There is plenty of info out there on the internet how to make Ethanol. Pondering doing it myself. I'm afraid I'll drink up all of my fuel though.

In order to get the most out of E85, you need to increase your compression ratio or add a supercharger. Then that 25% drop in mileage will shrink since you are getting more "squish". You also don't need the higher octane (and more expensive) premium fuel.

So if the higher compression helps, why not take a diesel engine, drill and tap the head somehow for a sparkplug, put a throttlebody on it, and have a direct injection, high compression ethenol engine? You'd have to run an EDIS type ignition, since there would be nowhere for a distrubutor.

Um, no. There are no diesel engines that match our transmission bolt pattern and besides, that's just far too much work. If you want to go E85 only, or optimize your engine for E85, just raise your compression to 12 or 15:1, 24:1 is overkill.

Turbocharging would be prefered if you are going for all out efficiency...

Air-Fuel Ratio
Gasoline = 14.7:1
Ethanol = 6.5:1
E85 (Theoretical) = 8.0:1


If you do the math, using the air-fuel ratio of double that of Gasoline, you should get almost a 45% loss in fuel mileage. I don't know why its only 25%, but I can assume it is because the computer adjusts the timing as well as the air-fuel ratio.The stoich A/F of pure ethanol is 9:1 and E85 is about 9.9:1. That accounts for a large portion of the descrepancy. (You are probably thinking of methanol which does have a stoich A/F of about 6.5:1.)

Compared to that of gasoline, the spark advance is increased by the PCM for the more advance-tolerant E85, giving back a portion of the fuel economy loss due to the lower unit energy content of the fuel.

Compared to that of gasoline, the spark advance is increased by the PCM for the more advance-tolerant E85, giving back a portion of the fuel economy loss due to the lower unit energy content of the fuel.With E85 in the system, the PCM also makes adjustments to fuel injector pulse times...

With E85 in the system, the PCM also makes adjustments to fuel injector pulse times...Obviously. BTW, it is injector pulse width.

BTW, it is injector pulse width.Yes, it is. On the other hand, I often use the phrase "pulse time(s)" and so I hope that you'll bear with me on that. ;)

FWIW, I recently came across this fairly detailed article on FFVs and Ford systems in particular:

http://www.babcox.com/editorial/us/us020628.htm

Something I learned from the article that I didn't know before is that Ford uses two different strategies with respect to how the EEC system determines whether there is any E85 (read: alcohol) in the fuel system. On 2000 and prior models, the PCM measures input from the flex fuel sensor. However, on '01 and later models, the PCM uses a software strategy known as "deductive refueling logic" to make that determination (which, IMO, doesn't appear on it's face to be as accurate a way of doing things).

Something I learned from the article that I didn't know before is that Ford uses two different strategies with respect to how the EEC system determines whether there is any E85 (read: alcohol) in the fuel system. On 2000 and prior models, the PCM measures input from the flex fuel sensor. However, on '01 and later models, the PCM uses a software strategy known as "deductive refueling logic" to make that determination (which, IMO, doesn't appear on it's face to be as accurate a way of doing things).Good article - thanks for the link.

I guess the good news is that the new method eliminates the sometimes troublesome Fuel Composition Sensor used on 2000-back Rangers. I've heard that the replacement assembly required to correct a sensor code is about $400 plus labor.

The new strategy is a clever way to do the same thing with out the Composition sensor. The Fuel Level sensor it uses was already there because of OBDII requirements and so were the O2 sensors. It's probably fairly accurate and should be able to make up for any errors with fuel trim.

I guess the good news is that the new method eliminates the sometimes troublesome Fuel Composition Sensor used on 2000-back Rangers. I've heard that the replacement assembly required to correct a sensor code is about $400 plus labor.

The new strategy is a clever way to do the same thing with out the Composition sensor. The Fuel Level sensor it uses was already there because of OBDII requirements and so were the O2 sensors. It's probably fairly accurate and should be able to make up for any errors with fuel trim.I hadn't thought about it that way before. Maybe Ford does indeed know what it's doing in this case. I suppose I'll keep an open mind. :)

I think any reservations that I might have are with respect to the heavy reliance upon the 02 sensors. It seems to me that they alone are being asked to inform the PCM that the driver has decided to dump some E85 (as opposed to regular) into the tank. So, what happens when a FFV driver with a 3/4 tank of regular gasoline adds 4 gallons of E85, then a few days later adds 8 gallons of regular, then a week later adds 6 gallons more of E85, then a week after that some more regular, then some more E85, and so on and so forth. In such case, are the 02 sensors and PCM really "smart" enough to figure out what's really going on? All that mixing of fuels in the tank and fuel lines with seemingly no true delineation between E85 and regular gasoline.

In a nutshell, with respect to this "deductive refueling logic", I'm having a little trouble grasping the notion that the 02 sensors and PCM can consistently and reliably discern between an E85 event and a good old-fashioned lean (and a less common rich) condition.

Deductive refueling logic simply watches for a refuel event by monitoring the fuel level. At the startup immediately after refueling, the PCM then looks at the O2 sensors for a slightly different purpose than normal. It uses the sensors to determine what kind of fuel the driver put in the tank. If the PCM is currently running unleaded fuel strategies and suddenly “sees” a lean condition at that startup, it assumes E85 was added and then uses its trim calculations to determine the amount of alcohol in the tank. After it has that amount calculated, it then resumes its normal “view” of what is “rich” or “lean” in respect to the type of fuel it “thinks” is in the tank. If the driver is switching from E85 back to regular unleaded, the same is true. The only difference in the switch back to unleaded is that the PCM will now see a “rich” condition upon restart after a refuel condition.

Moonshine is the same thing as Ethanol. They are both distilled from corn. Mix 85% Moonshine w/ 15% Gasoline and it should run just the same. There is plenty of info out there on the internet how to make Ethanol. Pondering doing it myself. I'm afraid I'll drink up all of my fuel though.


What about a mix of Everclear? Thats made of grain though, still work haha? ((190 Proof.)

Why is it, everytime there a a thread about Ethanol, someone has to post about drinking it, or substituting a ****tail for it?

The answer is Yes, but let's think about this...
Do you want to run Everclear at $23.95 for a 750ml bottle (http://www.beerliquors.com/liquors/grain.htm)? Let's look at the math...

There are 3,785.4118ml in a U.S. (not imperial) Gallon. So it would take over 5.04 750ml bottles (formerly known as "fifths") to make one gallon. Hmm, $2.75 a gallon for Ethanol (national average) or $120.71 for Everclear.

Now, I'm no math major, but I can see that it would be cheaper to fill up on regular gasoline and drive to a state that offers Ethanol, fill up on E85 and drive back for the same price as one fill up of Everclear.

But hey, say you're in a pinch and you run out of fuel while hauling cases of Everclear for your buddy that owns the local liquor store. You're out of gas, strapped for cash and curious, so what the heck. Fill up on his hooch!

In a nutshell, with respect to this "deductive refueling logic", I'm having a little trouble grasping the notion that the 02 sensors and PCM can consistently and reliably discern between an E85 event and a good old-fashioned lean (and a less common rich) condition.If I understand it correctly, the only time it makes a shift is when a refueling event has just taken place - in other words, the FLI input to the PCM says that the fuel level has just jumped up. To the computer, this means that there is now a possibility of a different fuel mix.

When the PCM sees a significantly leaner or richer indication immediately after a fuel level change, the chances are close to 100% that it is due to a new fuel composition. It then readjusts the center of the fuel trim to the current O2 indication. Regardless of how many times it happens or how much fuel is added or its composition, this should work.

The problems might start occurring at high miles when the O2 sensors get lazy just as they do on a vehicle that runs on gasoline only. Then the "refuel/best guess" system would probably not work well at all. But a new set of O2's should bring it back.

OK, so the fuel level sensor input is the trigger for the PCM to start looking for an elevated lean or rich condition that wasn't present before the fill-up. Gotcha. But let's kick that around a little bit. :burnout:

Suppose the driver, while at pump, decides to pop the hood and look things over. Not that uncommon. While checking the brake fluid, he or she somehow manages to knock loose one of the vacuum hoses that are in abundance in the same area, only a few inches away from the master cylinder, in fact. (Less common, but certainly possible). Said hose is not quite disconnected completely, but is loose enough to allow some unmetered air into the engine.

Under such conditions, wouldn't the PCM - having been informed of the resultant lean condition along with the increased fuel level - then be inclined to make the determination that a certain amount of E85 has been added to the tank, even though that's not really the case? At that point, as we know, the ignition timing and fuel injection tables would be adjusted accordingly, albeit erroneously. And to make matters worse, since the EEC system now believes that everything is "OK", it will fail to set any lean codes and light up the CEL which might otherwise informe the driver that something is amiss.

The end result is an EEC system operating under a false set of circumstances. That's not good.

I offer the “accidentally disconnected hose” as one example, but I can’t help but think that there are other circumstances wherein the PCM might also be “fooled” in a similar fashion.

But, the "sucking" sound under the hood, rough idle and poor acceleration should tip you off that you hosed something up. In any case, the "immediately after fill up" is within the next run cycle, I believe, because there is still old fuel in the lines, and it doesn't loop back like the return style systems.

So, sure, if that happens, there will be an issue. But there would be an issue regardless. I just want to be sure that people don't think this "look" at the O2's is a brief thing, or a snapshot. It's an "adaptive strategy".