I have a 2001 Mecury Sable with 28,000 original miles, fuel mileage is poor on 2001 Mercury Sable

car runs excellent, no fault codes are tripped, but I appear to be getting around 15 mpg in city driving.

Asked by for the 2001 Mercury Sable
Preventative maintenance for years, not mileage. Tune up, fuel filter, fluids.