I'm looking for advice on how to get maximum fuel economy out of a mostly stock '03 LB7. Really the only mod is a FASS lift pump/filter.

Most of my driving is highway between 65 and 80 MPG with no extra load.

I'm new to tuning and have only tried the "20-20 tune" so far. It works fine but doesn't really change the mileage and adds some noise.