How often do you change your fuel filter?
The NA I just got has 155K on it and judging from the condition of the transmission and diff fluid changes I have done so far, I would guess the fuel filter hasn't been changed every 30K either. I recall reading an article about how clean gasoline is these days and that it eliminates fuel filter replacements. Corolla has a (supposedly) lifetime fuel filter.
So have any of you changed your filter and noticed an increase in performance? Mileage? Did you go with Mazda filter or other?