dear friends, i would like to know how often / how long do you change the air filter of your car? i drive a 2 year old wira which only clocked 14800++km and only recently i can feel that the fuel consumption of the car has increased. i don't think its due to the tyre pressure as i've only pump air recently. could it be the air filter? cos from what i know, since the 1st service until today, i haven't even change the air filter during the scheduled car service, and there was once i tried to open the air filter box myself, i saw that the paper element of the air filter already in grey colour... it's clogged with dust i think. does this mean that its time for me to change the air filter? please help me... thank you!:_: