Tires.
go up a size taller.
I went from 245/45/18 to a 245/50/18 on same rim (infiniti q45 sport)almost a 6.5% increase in diameter giving me lower rpms at cruise.
Also ran 44psi.
If you have the option also go w/ a taller rear gear.
Gotta have a mpg gauge.
see the first link in my signature SCANGAUGE.
If my 3800lb
340hp 4 door can get 30+ on the road.....so can you!!!!
ps: i always keep the climate control ON