Originally Posted by DoomsdayFAN
What kind of gas mileage does a heavily built or fully built STi get, ballpark? Is there an "economy" tune to switch over to when wanting to save on gas and keep her running a little slower?
I can't speak for a fully built STi specifically; however, I can say that a fully built WRX WITH the STi guts (minus the ECU and AVCS) gets about 25mpg MAX...flat road, highway/freeway, straight, no traffic, at sea level, and very little added weight. City...yeah...it tanks...heavy foot =15mpg; light foot =17-18mpg. (...I also have the JDM 6spd...so 5th and 6th are a bit closer, so that will affect MPG some; +/- 1-2mpg)
*That is for a 16bit ECU (02-05 WRX), with the whole STi shebang..again minus the ECU and AVCS.