I'm running nothing but no-ethanol premium, is running 5 bucks a gallon here in Montana right now. I don't know anything about the technicalities covered in this thread (or at least I didn't until I read it), but what I do know is that my 95 Suburban 454 went from 12 mpg to -7-8 mpg, when I tried running ethanol in it, and my 89 Crew cab 1 Ton TBI (shortly to be a quadrajet) dropped to even worse mileage than normal.
As an aside, one of my wife's uncles was a pretty well-respected ag economist out in IA, for many years, and he's got absolutely nothing good to say about what the whole ethanol thing is doing to good farming practices. The sooner the whole ethanol thing ends, the better, as far as I'm concerned, particularly given what food prices as likely to do in the near future. (And that's something I do know the technicalities of, being the father of 7 kids between the ages of 15 and 2). I'm gonna send those !@#$#-es my next $900 grocery bill, for a month, and tha's raising my own pigs and shooting a whole pile of venison every year.
Aaron