Just fueled up with E30. I have a Flex Fuel Vehicle. Surprised me that the E30 was 40 cents per gallon cheaper than the E85 (51%-83% ethanol). Figured higher ethanol content would mean lower price. What gives?
You need to convert to BTU and figure out the math. Sometimes E85 has more than 15% gas so your gas mileage is actually better than expected.
E10 has 111,836 btu's per gallon. E85 is at 81,800 or about 73% of the energy content of E10. So yeah, E85 at $2.21 is a better deal. For me though, I just filled up with super at $2.99 a gallon so E85 is still more expensive and I'm far from the corn belt so E85 isn't even that cheap in this area.