Just filled up with about 207km on the tank.
Overall, I managed 4.58 l/100km, or about 52 US mpg.
90% highway, always going to the speed limit (100km/h, 62mph)
When going down hill, I would slowly accelerate to about 110km/h (almost 70mph), then release the gas pedal and let it coast (in gear, so you get the effects of the fuel cutoff), then give it gas again when it hit 95km/h. No drafting , and no driving under the speed limit. And yes, I used the same pump as the previous fillup, and even filled it to 3 clicks since I didn't believe it at first (last fillup I only went to 1 click)
Needless to say I am very happy. 1600km about on the engine now.