Sorry for not posting, I've been on vacation. I drove my wife's van, a 2002 Chevy Venture minivan with 62k miles. Seeing as how this is a very used vehicle (as opposed to my 6 month old Saab) and not under warranty, I don't put E85 in it.
Meijer had E85 for $2.75 a gallon yesterday. Even though I wasn't on empty, I filled up with E85. They had 87 octane gas for $3.25 a gallon, so the spread between E85 and regular has opened up to 50 cents a gallon. Nice.
My mileage on the previous tank, which was 30% ethanol, was 23.5 mpg. This is about 1 mpg less than I normally get on straight Amoco Ultimate.
Stats for the new tank:
Gallons E85 (70% ethanol): 7.508
Gallons 87 Octane gas (10% ethanol): 4.595
Gallons left from last tank (30% ethanol): 4.297
Ethanol content of new tank: 42.71%
Octane of new tank: 95.147
Fuel savings (E85 @ $2.75/gal, 87 @ $3.25/gal, 93 @ 3.45/gal): $6.17/ tank
So far I've driven about 20 miles. Driveability is fine and no check engine light. Mileage is attrocious so far (19.8 mpg) but I did drive about 5 miles of local last night. The drive to work this morning took it from 11.8 mpg to 19.8 mpg. I had the cruise set at 65 mph where I could on Cline Ave. That's my new top speed!
I also pumped up the tires to the max they're rated for, 35 psi. Ride is QUITE firm.
The drive home should be interesting.