Ethanol/gas mixes (was: premium vs regular)

[Achille Riviello <acriviel@mailhost.ecn.uoknor.edu>]

Believe it or not, here in the oil patch (Oklahoma), it is very hard to find
gas with an octane rating above 91.  In Virginia, I used to get 93 at the
7-11--go figure...  Now, I normally use a 10% ethanol/gas mixture that rates
at 91 octane.  I can't seem to see a difference in performance when I switch
from a 91 pure hydrocarbon gas to the 10% ocatane.  Is there any potential
problem associated with the ethanol/hydrocarbon mixture with respect to
engine performance/reliability?  Thanks in advance.

Achille Riviello
acriviel@mailhost.ecn.uoknor.edu
83 4000s, 200+k miles,
96 A4Q, 617 miles,
HK USP45,
HK P7M13
HK P7 PSP 
"In a world of compromise, some don't"--HK