sigh my fc is seriously something wrong. tyre pressure ok, engine still new (8000km?), footing average, not much change in travel pattern, car is stock, spare tyre still at the back.. ... last 2 tanks 11km/l 
this tank also i think near 11km/l. what can be wrong man.
bro, the road conditions play 50% of the cause, last time KPE not open yet, my FC 10-11. Now after KPE open my FC 13-14
travel and driving style not much change. just one day a week travel abt 120KM to Tuas and back.
Tyre pressure 250 front. 230 back
FYI initially when u change to Fully Syn oil, u notice yur engine super quiet, and a bit sluggish. thats normal. it takes abt 1K+ to run in just take it easy and not rev too much.