Bunch of hippies

.
I am just silly

. Love a good mileage myself to. But I must say I had to (btw it was my girl who pointed it out) rev a little higher. I always tend to drive 80 km/h in 5th gear. Since more than half my home-work route lies on 80 km/h roads (roughly 50 mph) she told me to use 4th gear instead since the engine revs are too low otherwise.
Doing so saved me more than 1km per liter and I finally managed to get my old mileage which I had years ago (but back then I drove 120 km/h road mostly, not 80!). I even had one fill up of about 1:16.5 doing so, very close to my all time record since I installed the VTEC cam.
So point of the story, don't shift too soon. It seems best to keep partial throttle so the lambda sensor does its job. Don't go into full throttle (WOT). But rev a little more.
Doing so my current average mileage of the my D14A3 went from 1:14.5 to 1:15.5.
The bone stock D14A4 of my girl can also get close to 1:16 driven good. However on a bad day with a bit too much WOT and too low revs (my girl often falls back in a rythm of early shifts combined with WOT) it seems to drop to 1:14 (liter:km).