@jazibb: excellent avg but you are ruining your ignition coils, leads and battery.
@ rest: shocked to hear that few of you are getting avg of 9-12 km/Liter.
Normally the car gives around 12- 15 km/liter of avg where i dont understand the in India, same car with same body and engine is providing 20-23 km/L. (petrol quality could be an factor)
So I would suggest, to check what Tyre size one is using with how much psi it is filled (for reference kindly check driver door where recommended Tyre along with pressure is indicated).
Secondly by increasing the gap, one is overloading the battery, ignition system and its related leads which isn't recommended at all.
if one wishes to get better avg, then it is suggested to use spark plugs that are mentioned on the inner side of bonnet either with normal or iridium/platinum tipped.
i am sure you guys will get better averages if correct air pressure is filled in Tyre rather going for change of spark plugs or increasing gaps.