you wont get 300 in the city.

i ususally got 200ish 100% city driving (delivering pizzas) with a lead foot.

to improve, clean your UIM, LIM, and TB (check the how-to section)

new plugs and wires

new air filter

use some fuel injector cleaner

lighten your foot (dont drive like a maniac)

Russell Oval Port 3L Nearly Done MTX75 w/ Homebrew Zetec FD and Torsen Complete