E-85 is cheaper here in Minnesota. How much do I ricchen my 82 rabbit PU without EGR or O2 stuff to run it?
BTW, I think that ethanol is a terrible solution to energy problems, almost a smokescreen. It requires a sht ton of energy to cook and distill the stuff. But I would like to try it. I also know that it contain less energy than gasoline. I am a mechanical engineer student turned civil.
No one can really answer that question for you. The tune-up procedure is identical whether you are running on gasoline or ethanol, so you need to adjust it so that the CO level out of the test pipe (on the exhaust manifold) is .6% or whatever is specified.
Ethanol has a number of issues, some positive, some negative. It contains less energy per gallon (or per pound) because it contains oxygen. This is a double edged sword, while you are only getting 2/3rds the energy, you are also getting in a lot more oxygen, which means the car will make a lot more power if properly tuned for it.
On the bad side, a number of metals, rubbers, and plastics which are compatible with gasoline are not compatible with ethanol. It's definitely possible to get meterials that are compatible with both, but long term, unless you know all the materials in your fuel system are compatible with ethanol you may be asking for serious problems running ethanol.
I also question how compatible the two are in terms of "octane", its possible your ignition timing may need to be changed (and not just resetting the base timing, changing thhe whole timing curve), and you won't really know whats right other than by listening for detonation. A modern vehicle that is designed to be compatible with ethanol, and with modern electronic fuel injection should be able to handle ethanol as easily as gasoline with no downside, but I'm not so clear about an 82 Rabbit.
As for the "smoke screen", I think this issue isn't very clear either. I've heard its net energy negative, but I haven't heard conclusive proof of that. Also, thats in reference to corn-based ethanol. In Brasil for instance, sugar based ethanol is very common, and its much easier to get ethanol from sugar than corn. Difference is, US has tons of corn, and Brasil has tons of sugar. Ethanol based cars are very common in Brasil nowadays. If ethanol is truly cheaper than gasoline (per energy) and the car is designed to run on it, its definitely a better choice than gasoline.
I am fairly sure that earlier cars -- and 82 would certainly fall into this -- have seals that are not ethanol compatible. I recall warnings about so-called gasohol, which was the early alcohol-enriched gasoline.
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You mean you weren't civil before? Tsk. Tsk.
One thing that is lost in the ethanol debate is that ethanol is also a replacement for the MTBE that is no longer allowed in the gas. So, the cost etc of ethanol needs bounced against not only the cost etc of "petro-gasoline" but the cost etc of MTBE also.
blah wrote: > Ethanol has a number of issues, some positive, some negative. It contains
Not true. Less energy means less power and less fuel economy. Period.
Ethanol has lower energy *density* than gasoline, but if you can burn it faster than gasoline (which is easier to do since it contains its own oxidizer) then you can still get more power. *Lots* more, even. Do you think that F1, Champ, NHRA, etc. would use alcohol if you couldn't get plenty of power from it?
-- Mike Smith
Ethanol doesn't have "less energy", it has "less energy density." Meaning you need more of it (either by volume or mass) to get the same energy. This means that it has "less fuel economy" assuming your metric is distance driven per volume (or mass) of fuel. If ethanol were cheaper than gasoline, you may still have "better fuel economy" if you are measuring it as distance per dollar.
Less energy density has nothing to do with power output however. The "limiting reagent" in an internal combustion engine is oxygen, plain and simple. The more oxygen you can get into the combustion chamber the more mechanical energy you can get per combustion event. Since ethanol contains far more liquid oxygen than gasoline, and liquid oxygen is denser than atmospheric oxygen, you can get more power with ethanol since power is essentially proportional to the amount of energy per combustion event * number of combustion events per unit of time (rpms)
Hmm ... I'll buy that. I stand corrected.
According to Car and Driver, their E85 test vehicle was way slower and got much worse fuel economy than regular ol' gasoline. How come?
A car optimized for E85 would have a much higher compression ratio. That car could retard the spark to burn gasoline in a pinch. To be fairly optimum for both, it would need something like a supercharger that boosts higher for E85.
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