I found that recently 93 octane has been getting up there in price (uncommon to see the 20 cent markup anymore), and I am soon switching to E85 in my DD stock GTP (with 3.2 pulley) so I have been experimenting with different E85 blends in the mean time.
After much experimentation, and a bit of math, i was able to run e30 (there is a pick-a-mix e85 station in greenville) without causing any gruff to the stock fuel system, and I run very easily with zero KR ever in the cold even... Fuel trims that are normally a few positive are now about +14.
Next time you are at the gas station with E85 fill up 3/4 tank with 87 and pile in e85 on top. A 25% to 40% e85 mix will run just fine in a stock GTP, or a modded one with room in the injectors. If you see a check engine light it means you will be running slightly leaner than 14.7 at cruise, and a little lean at WOT, which on my stock car did not cause any problems.... I expect even a edge tuned car to have no issues either.
I also plan on doing this in my TBSS during the summer.
