picked up a 97 gtp, stock except a "hai" and flow master mufflers, i had to drive 3 hours to get it home and i got 29mpg which is what i was expecting and now that i have to home over the last couple of days its gotten worse little by little, i put in double platinum "oem standard" plugs, msd wires sea foamed the engine and am only seeing 14mpg. i do live in a city and there are a lot of street lights but should i not be getting closer to 17mpg? or am i just expecting too much of the car?

i havent manually calculated the mpg but will do so the next time i get gas