how will ethanol affect my fuel mileage ?

1968FormulaS340 said
Well, 250 miles off a WRX tank (over 16 gallons, 16.9 I believe), is bad. That's under 15 MPGs from a car that should get high 20s.

That is significant.

Sti lol doesn't get high 20s it gets 21-24mpg highway, with gas. And he drives it hard everyday. Drives it like every light is a tree.