Great news for allof you..
actually mielage in newly imported car has nothing to do with oil, plugs etc.. i discovered it few days back on a japanes web.. what happens is that all of you can get avg of 19km/ L on odometer with just this technique.. though it is difficult but it is economical
DRIVE YOUR CAR IN A WAY THAT ODOMETER LIGHT REMAINS ''GREEN''( talking about light which becomes blue,orange etc)
For your info: it is also called assist light .. it assist you; tells you that ur driving style i sECONOMICAL
{ We have used sophisticated equipment that takes account of actual fuel consumption and supports eco driving in a way that is easy to understand.
(1) The Eco Drive Assist light changes to green when the driving style is fuel-efficient.
(2) The Eco Drive Assist Display indicates the amount of gasoline saved and energy regenerative status at deceleration by means of the Eco Power Generation Control
(3) The Multi Information Display indicates engine stopping time activated by eco IDLE, the accumulated time, average fuel consumption etc.}
source: DAIHATSU - News
dont forget to thank me if it works for you