Bob- I used cruise control repeatedly over a ~100 mile section of interstate at 65 miles per hour. All days were cold, in the teens and 20's outside. No significant wind... not enough wind to bump the car around that I was aware of. Winds were light, and a cross-breeze.

E10 Sold for $2.899
E85 Sold for $2.169 during one tank of testing.

That makes E85 about 25% cheaper cost in my town.

3.5 x $2.169 = $7.59
11.5 x $2.899 = $33.34

15 gallons of E30 fuel cost $40.93 or $2.728 per gallon.
A savings of $2.565 per tank

15gal x 27.5 MPG = 412.5 miles traveled at 65 miles per hour cruise control, E30.
15gal x 31.0 MPG = 465.0 miles traveled at 65 miles per hour cruise control, gas only.

52.5 extra miles, if from pure gas would equal 1.7 gallons and if from E30 would be 1.9 gallons.

So really, E30 is costing me more than gas I think.

But the whole point is, E10, which is what most people are forced to use will cost more extra per tank, when compared to gas only.

This is a "premium" fuel with a premium price. E30 is about 97 octane, and has a large effect on cleaning up emissions, and you will also use 30% less gasoline, which equals about 10% less foreign oil use, since some foreign oil is used to manufacture the ethanol, of course. E10 is only saving about 3% oil, and costs more per mile than E30.

I just mixed 3.5 gal of E85 with 11.5 gal of E10, since all gas in MN is 'supposed' to be E10. The Ford Escape reads "empty" at about 14 gallons, but really holds about 17 gallons.

To use, or not to use E30 is a personal, and complex question.
However, I think E10 is currently a bad choice.
My personal choice is to use 30% if possible, as there are more benefits to it than E10.
-John

P.S. I'm visting So. Cal. and "regular" gas here has 6% ethanol and costs $3.359 near my folks house.