My DD is a 6th gen accord,

I've been keeping track of how much a full tank gives me on mileage..

a full tank(which is about 15-16 gal) gives me enough for exactly a week or an extra day

it hits 350-365

lately its only hit 320

most of it is hwy mileage

i changed oil, intake filter, oil filter, spark plugs, and about to change my cat. converter

besides a tune up... is there another option for me.. if i want to get a bit more mileage??