Folks:
Some interesting comments made in defense of and against of ethanol
in fuel. Thought I would attach some information on the pros and cons...
CARB paper citing increased evaporative emissions with ethanol
blended gasoline:
http://www.arb.ca.gov/fuels/gasoline/meeting/2006/063006onroad.pdf
Senator Diane Feinstein's position on the use of Oxygenated fuels:
http://feinstein.senate.gov/05releases/r-epa-oxygenate-reject0602.htm
EPA paper on emissions effects of oxygenated fuels:
http://www.epa.gov/oms/regs/fuels/ostp-1.pdf
I can summarize the last paper for those of you not into tech
papers:
Under summer driving conditions CO and HC emissions go down with
oxygenated fuel usage, and NOX emissions go up.
Under winter driving conditions (ambient less than 50F), HC, CO
and NOx emissions go up with oygenated fuel.
The addition of ethanol was originally conceived as a winter fuel
program, which means the use of ethanol is problematic.
(Ahem). I will eat (at least part of) my previous words (Dave, are
you listening?). Ethanol can and does reduce emissions, under certain
conditions. Many studies show the benefit of ethanol, but they have been
offset by more recent data showing that testing conducted under narrow
conditions (fully warmed up cars under summer conditions) overstates the
benefits and completely misses the downside. CARB feels that it is not
good trade off, and wants out of the program. I do stand by my claim
that the clearest benefit is for older vehicles, which are a very small
portion of the fleet these days. The winter fuel program is still in
force throughout the country.
OK, there you have it. I wanted to correct the misinformation I
spewed earlier.
Cheers,
Vance
|