Welcome to Ecomodder...
It looks like the average is 5.5L/100Km combined cycle, so you might be able to get it down to 4 in town. What is your typical in-town drive like?
If aggressive driving gets you 6, try some of the city driving tips in the 104+ tips link. That will give you an idea of how much you need to do...
If you'd like, tell us more about your car -- we don't get cool little cars like that around here
Best FE,
RH77