Nice thread. I am also a semi hyper-miler
I used to get 19-23km/l every time i drive my car to university(17km route)
now i get hardly 20-21km only if i drive for 3,4mins on 5th gear and average is between 14-17 now.
Oil is changed on time, Tire pressure 30-35psi, NO CNG, filters are good.
i change gears usually on 3rd gear 25-35km/h, 4th max to 45-50km/h, 5th from 50 onwards. No low pulling(change 1 n 2nd gear under 2k Rpm till 30km.
Car: Yaris 99 manual with average meter display