aiyoh.. so hard meh? try this... go pump full tank... reset your
tripmeter or note the mileage... the next time you top up your
tank, see how much fuel was used up. then calculate it based on
upon how much u travelled (tripmeter or odometer)... so u'll get a
km/l number, just multiply that by your tank size lor.. settled!
repeat and average it out for more accuracy... 
