Replace...
Spark Plugs
Plug Wires
Air Filter
Fuel Filter
Oil change
Seems like you have gotten the majority of the regular maitence done. I think your economy is decent. My tour is getting about 23 City right now because of the colder weather. I never got an NOTICEABLE gains on the freeway until you spent about half of a tank on the free way. Next time you spend about 100 miles on the freeway from a full tank, stop and fill it back up and do the math (I assume you know how too), it should be between 31 and 34 MPG. I get abotu 32 MPG on the freeway. I can never see any gains on occasional trips on the freeway.
