great thread of informations here. thanks everyone who has contributed so far.
now, i've recently bought this Passo 1KR-FE (VVT-I) 2008 Model.
and my personal results (based on last 3 months) are as follows
Without A/C = 14.5 Km / Liter within Lahore city, subject to traffic jams.
With A/C = 12.2 Km / Liter within Lahore city, subject to traffic jams.
Without A/C = 21.1 Km / Liter on highway (I usually travel from Lahore to Faisalabad through motorway)
With A/C = 18.9 Km / Liter on highway (from Lahore to Faisalabad & return through motorway).
Do not push the accelerator too much. because high RPMs of Engine consumes more fuel.
At-least once in a month, try to drive the full tank on "high octane". It will increase average min. 1.5~2 km/Liter.
or, try Half tank with normal petrol and half tank with high Octane. It will increase the average min. 1 km/liter. and also good for Engin's health.