Guys, just wanted to ask if you guys experienced your car engine stalling at neutral gear, even at a complete stop. I'm driving a manual spec and it happened a few times. It's not a rough stop, rather it felt more like it was gradually dying. Anyone had any experience of fixing this? What should I be looking at?

spark plugs or ignition coil perhaps?

or, it might cost by the O2 sensor as this symptom kind of related to engine combustion.

hope this help.

gen 1, drove before for 2 months
city drive with jams and slow traffic
full tank-450km

city 50%+highway 50%
full tank-500km

highway 90% @100~110kmh
full tank-700km
i personally own gen 2,
gen 2, drove before for 2 months
city drive with jams and slow traffic
full tank-400km    

city 50%+highway 50%
full tank-bet 450 to 500km

highway 90% @100~110kmh
full tank-700km

gen3, according to friend

city drive with jams and slow traffic
full tank-450km

city 50%+highway 50%
full tank-500km

highway 90% @100~110kmh
full tank-700km~750km

disclaimer: this is from my own personal experience and will be different from others. your foot makes alot of difference on FC. till now i still unable to control my foot during slow drive, like after bump, the car transmission damn stupid will downshift and creating an unnecessary accelerating power which causes high FC, guess toyota drive by wire tech is not that good during the 2nd gen vios. 3rd gen vios have better drive by wire tech + lighter body. that's why you see a reduce of FC in the new vios

Vios is damn bloody light and float car bro... not feel secure in it riding high speed.