Mine was getting the excact same mileage, until I replaced the fuel filter. My mileage has gone up quite a bit. I also do mostly city driving, which doesnt help.
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98.5 Contour-Zetec w/ auto (doh!!)-modified stock airbox
res and muffler removed glasspack added-Knauberized
Pioneer CD-Alpine speakers in all doors-2 pioneer 10" subs
mesh grille-side markers
painted dash