>at $1.74 it gets costly....

Wow!! were do you live at ??? Here in the Bay Area (Cali).
gas runs anywere from $2.09 - $2.19 per gallon !!!

Anyway, to answer your question the turbo does effect gas milage only depending on how you drive, but that is the case for NA or turbo. you cant tell me you can get 300 miles to a tank of gas romping on your car 24/7... Well the same applies to the turbos, but when under boost even more gas gets consumed. When not in boost i noticed near stock gas mileage..

hope that helps !