[jugger]

i pulled my fish tank filter out and saw no difference in MPG. but i regularly get 18.5 mpg back and forth to work and 19.5 mpg on the interstate (and thats at 75mph)..
i think what you guys are seeing for mpg increase is the reset of the ecu. i reset my ecu at the end of winter when i notice my truck was running slower than i remembered. after the reset my mpg went way up from 15mpg and truck felt so much stronger. these two factors go hand and hand>>>> lean out the Air/fuel ratio and you make more power which results in less fuel consumption

i had to do this ecu reset from time to time on my old WRX to get better fuel milage and more power. with the WRX it was more obvious because my wideband Air/fuel gauge would read rich and EGT gauge would read colder