What kind of mileage are you getting now?
What do you mean by "sadly i think i've only had her on a full tank of gas maybe 3-4 times since i've taken ownership"?
Are the tires stock size?
By well maintained, does this include all fluids, transmission, fuel system, throttle body, COPS, etc.?
If you decide to purchase a tuner (despite the overwhelming evidence against them improving MPG), please stay away from Jet. Look into SCT or Gryphon/Edge with custom tunes.