how will ethanol affect my fuel mileage ?

Fst73_360 said
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.

Just so we can move along.... Because this thread isn't about the MPGs of a Subaru.

It's still a loss of 5+ MPGs which is significant. That would be in the 20+% loss range, along the lines of what others here have mentioned.