Gasohol is a mixture of roughly 80-90% gasoline and about 10-20% ethanol (Usually) or methanol (more toxic - MTBE is a methanol based additive more commonly used). Each alcohol has pollution, cost, or performance trade offs. From what I recall from my Environmental Chemistry and Atmospheric Chem colleagues, gasohol tends to produce less of some pollutants, but more of others (typically oxides of nitrogen or formaldehyde - depends on the alcohol) than does 'pure' gasoline. The fuel provides a bit more power and a bit higher octane, but requires a larger gas tank for equivalent range, and it tends to accelerate engine wear and wear on seals and gaskets. It tends to increase transport through the soil and into the water table of spills from leaking storage tanks, and it is not a very economical choice, being driven primarily in this country by midwest Ag politics and government subsidies.
That is pretty much most of what I recall - I may have botched some of the details. There is a site called Ask Jeeves ( http://www.ask.com
) that will probably have a number of articles or additional sources.
2003 Firemist Red/grey leather SL 500
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1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
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