Welcome to StiLtd.com,
There are many great sites about Subarus and in particular the WRX and STi versions of the Impreza so I won't try to duplicate what they have already done. I'm just putting up this website to show the mods I've made to the car.
The main thing is changing the injectors & fuel pump to change over to 100% e85. I used the standard Walbro pump and 1100cc injectors. Access port allows tuning. Other than that and a KN air filter, nothing has been done to the engine.
Other mods: Volk Wheels, Coilovers, an X-Brace, a bunch of JDM trim pieces including the dash, door sills and front grill.
Best sites for e85 station location are:
US Govt (afdc.energy.gov)
Best fuel mileage with 100% e85 came on 3/12/15. A 161.7 mile trip took 8.6 gallons of e85. The car was driven 90% highway, one part hilly, the rest flat. No A/c, driving the speed limit and no rapid acceleration. This comes out to be 18.80mpg. Compare that to the official government number of 23mpg on gas and you see e85 doesn't have to mean plummeting mileage. That's only a 20% drop and that's assuming you believe the government's numbers. It's the tune and how you drive. Tune for max torque at very low boost, use that torque w/o getting into the boost heavy and upshift as soon as you can. Keeps the revs under 3K at all time. 2200-2500 seems to be a good spot to shoot for.
Things that helped get this number:
So the next time someone tells you e85 will kill your mileage you'll know they have their foot in it all the time. ;-)
Highlight the features of the Limited edition in the hopes of generating more support for this type of vehicle. When you buy the Limited, you get the following changes and additions to the Impreza WRX Sti:
Disclaimer: This site is not endorsed nor sponsored by Subaru. I do not work for Subaru, I just like the car.