Mex,
**** Caution - Long, Technical and Possibly Controversial ****
==>> But you asked.
This will be running very close to political here, so this may get cut, but I hope at least you get to read it before it does.
For several decades, I worked in and finally ended up running contract automotive testing laboratories. One of the first set of tests we did and even built several prototype vehicles for were fuels "enhanced" with either methanol (methyl alcohol - CH3OH) or ethanol (ethyl alcohol - C2H5OH). Both were found to be damaging to the current fuel systems, so ours were fabricated completely from stainless steel (mostly 316) and teflon.
We able to build and test the prototypes, but only the methanol had an advantage and only when used neat (nothing like gasoline in the mixture). These vehicles could take advantage of the high effective octane, but were hampered by the low specific energy of the fuel. It took nearly twice as much of either version to equal the energy available in the motor fuels of the day.
Yes, we did speciate the resulting combustion by-products and they were different and very toxic, but nobody was interested in the fact the these were aldehydes and amines that were water soluble. We also had a hydrocarbon analyzer that the EPA did not recognize because it gave different results than the stone age FID (Flame Ionization Detector - counts carbon atoms only). This was an instrument was a laser calibrated FFT (Fast Fourier Transform) device that could speciate hydrocarbons in the sample stream real time as opposed to the soluble capture that had been the accepted methodology.
What we did learn that nobody wanted to hear (my paper was reviewed and refused) was that not only was the alcohols not actually any cleaner a fuel that refined petroleum. The combustion by products were different, but "nasty". So emissions protocols using old measurement equipment saw a slight change. This lead us to another study that I will explain down the page.
Indy (CART) cars were running methanol exclusively at one time. There were two big problems. The pit crews had to wear gas masks during stop because of the exhaust, and a real gothca on a couple of occasions was that a fuel fire in the pits could not be seen as the alcohol flame makes very little light (not much carbon).
When the emissions study was contracted, we already knew what the results would be, but we had to get results that were what the client wanted if we were to get future work (and get paid for what we had done.) We quickly identified that then current (pre-catalyst) engines that were tuned to the manufacture's specifications showed no improvement with any alcohol addition to the fuel and in fact many were actually worse because of the additional fuel volume required to make even road load horsepower. The we resorted to bring in privately owned vehicles and running full road emissions on those. The EPS test at the time required that any vehicle tested be confirmed to be tuned to specification prior to testing. So, that was what we did.
Then somebody screwed up and brought us a student's car (ill treated and out of tune) and we set it up on the rolls (chassis dyno) and ran the strip. It was terrible, but it sounded terrible when it was driven in the lab. So, we took it off and changed fuel. Then, we ran it out on the highway to clean the combustion chambers. When back on the rolls, it was much better now. Not a lot, but enough for the those that wanted to to make the point. That "better" only showed up on the old emissions bench (the one with the FID). It was not evident with the data from the FFT based bench. (Less carbon - remember) We wrote the report first. The we tuned the same car up as it should have been and did the same tests. It came out almost no different with the alcohol mixes that it could run. It still look better with the FID and the CO NDIR, but then again, it was burning less carbon.
The final reports did not include the data from the FFT train of instruments.
I now own and run a 70's vintage coach. When I can get fuel that does not contain alcohol, I can get an improvement in fuel economy that is just about proportional to the alcohol content.
In an effort to keep this non-political, I will stop right here.
Matt
