a friend's 2006 Honday City with mileage of 40000km has this problem we're unable to solve since the past couple of months: oil consumption.
the car is maintained by Honda Classic I-9 every 3000km. the very first time, oil simply vanished into thin air because we never saw it dripping on the floor. put in a new box at night but again it was empty the next morning in the garage. found out the oil filter had not been fit properly. since then, it's common practice for the car to deliver less oil than put into it.
honda recently changed the oil ffilter as according to the service manager Taimoor many City owners complained of the same but i still see no change.