im having the same problem. i had just changed the coolant almost two months ago, i just drained the radiator and did not flush it. im filled it up with a shell coolant (grey container) (300 pesos/L) initially at 1:1 ratio. im loosing about 0.5L a and im just topping it up only with distilled water dahil mahal yung shell coolant. im just wondering if its possible that the new coolant might have something to do with this or is it because i did not flush the system?

suggestions/recommendations?