E85 and ethanol mythology
There really isn't anything to fear here, just a lack of understanding. Lets start with flame temperature. Lots of folks seem to have the idea that higher octane fuel burns at a higher temperature. This is not generally the case. Ethanol, with an octane value of something like 119 (R+M/2) burns at around 1200*F. Normal 87 octane gasoline burns at 1450*F. Then there is the BTU per gallon issue. There lots people foaming at the mouth about how ethanol has less BTUs per gallon than gasoline. Its true that it does. Gasoline is 120K and ethanol is 80K per gallon. The problem comes when folks think that BTUs per gallon and miles per gallon are directly related, and in a linear fashion. It just isn't that simple. There is much more to consider. An engine's thermal efficeincy is also greatly affected by the flame speed of the fuel used. In our case, gasoline burns at .34 mps, and ethanol burns at .43 mps, significantly faster. What this means is that more of the 'push' from the flame front moves the piston instead of just heating things up as it exits the chamber. Ethanol also has three times the latent heat of vapourization as does gasoline. This, along with ethanol's greater octane rating allows the use of much more compression than gasoline, even racing gas. The increased compression will help fuel ecomony greatly. Many test have shown a loss of up to 30% in fuel economy when using ethanol mixtures. But the same tests have some cars getting nearly the same mileage. Why the differance ? Ethanol, with a much greater content of oxygen, will confuse the O2 sensors in the exhuast of many cars. The computer reads the extra oxygen and thinks the engine is too lean, so it tells the fuel injectors to squirt as much as they can. This will usually give a very powerful and smooth running engine engine, but it will consume fuel like there is no tomorrow. Ethanol's range of flammability is greater than gasoline. This means that ethanol can burn both richer AND leaner than gasoline can. If you're looking for power, you'll want to jet rich to get it. If you're looking for economy, you may want to keep the fuel trim almost the same as gasoline. In any case, you need to watch fuel trim, too lean can burn things, no matter what the fuel. Then there is the corrosion fear. It just doesn't happen. Ethanol, in and of itself, doesn't corrode anything. But ethanol is more likely to get contaminated with water than gasoline, and the water can cause problems. Now, as long as you have a sealed cap on the fuel tank, I don't see why there is anymore risk than with gasoline. The kinds of rubber that ethanol can break down aren't used anymore. Most auto manufacturers began using ethanol tolerant seals and gaskets in the late seventies when 'gasohol' became widely used. If you are worried about your nonmetal fuel lines, buy new rubber hoses and then forget about it. There were lots of the same fears when we switched to unleaded from leaded gasoline. Lots of mechanics were predicting the end of the world, hairy palms and baldness and various other disasters. It just didn't happen. It won't happen now with ethanol either. If you want to expeiriment with ethanol, you should. But if you don't, then don't. But if you don't want to use it, you don't need to be bad mouthing it to others who want to try it. Unleaded and leaded gasoline were sold next to each other for years, I think we will see the same situation with ethanol. DF, @ his Dad's house
http://en.wikipedia.org/wiki/E85
http://www.answers.com/topic/e85
Dino must have an economic interest in pushing alcohol fuels...
Last edited by Torque1st; Jul 24, 2006 at 08:17 PM.
We should be pushing our senators and reps to make and agriculutal initiative to grow corn and cane to help out the gasoline "shortages" that we are experiencing with our supply and demand economic system. Get the ethanol plants online. The alternative explaination is that the big Oil Companies are practicing subversion and sedition on the U.S. of America.
We need fuel for internal combustion engines and I don't give a rats rear if its E85, biodiesel, propane or gasoline as long as it aleviates me spending 40% of my income to go to work and take care of business.
I am currently building a 351W for my '86 FSb and would prefer to build one to run on E85 but its not available within 450 miles of me so I'm going to build it to run on Pane with the option to convert to E85 later. That puts a whole new meaning to flex fuel.
Electric? We'll see how Tesla Motors does with their plans of a competitive electric sports car next year. Plug-in electrics could be a great solution for city drivers. Biodiesel? As you mentioned, another good alternative.
The whole idea of alternatives is that there are alternatives. One may win out over another, but hopefully it'll be because of fair competition and not political nonsense. And you are also spot on in that we should all be writing/calling/screaming at our Senators/representatives. It took a CAFE credit of 1.2 MPG to get Ford/GM making FFV's to run on ethanol. Let's give them the kick in the butt needed to start producing the cars needed for the future. I salute your efforts to change yourself over to alternatives, but real change will come when there are cars on the market in this country that will use these alternatives.
-Jim
Last edited by PSKSAM2; Aug 10, 2006 at 03:29 PM.
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Just don't expect alternative fuels to lower your cost per mile of operation. One of the reasons that alternatives are coming on line now is that they can be produced at a profit relative to the current oil prices.
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My brother has a dedicated CNG car that he uses for work as a building inspector. It is only usable in the city, like a battery-electric. He has to own, mantain, register and insure a second gasoline-powered one just in order to travel outside the area.
Jim
One change I can see with gasoline, however, that instead of the usual 3 pumps (normal, mid, super) there will only be a single pump with a pushbutton or dial selector for grade. And diesel will probably become mainstream even in the US, and the majority of new cars will be hybrids since they're superior to others in cities.
The two other options will be hydrogen once the technical hurdles are resolved, and electricity, either using some kind of battery, or a fuel cell.
Of course, this is all IMHO, but I'm 99% sure on all my choices except hydrogen. However, by the virtue of no greenhouse gases, I think hydrogen will win over ethanol, or gaseous fuels containing carbon like CNG/LNG/propane/butane/etc.
Last edited by aurgathor; Aug 11, 2006 at 12:24 PM.
I do already see gasoline pumps with a single pump and a selector for grade. Most pumps around here are like that. What I think would be neat, is a pump where you can dial in your exact desired percentage of ethanol. It would have a dial, and turning this would raise or lower the percentage of ethanol in your gasoline. It would also have a display showing the price per gallon at that percentage, and the resulting octane rating, which the station owner could vary based on a linear function of the percentage of ethanol. Then you push in on the dial to lock in your selection and start the pump!
Yes, I've been dreaming again.
It wouldn't be too hard to mix in extra ethanol when pumping.
Last edited by aurgathor; Aug 11, 2006 at 02:23 PM.
That would be the OTHER point.






