I have a 2017 b38 118i
I noticed that the coolant level was a bit under the minimum, so I went ahead and bought some coolant from bmw (HT-12) and topped it off. However, I noticed that the colours (both green) don't exactly match. Could this just be due to the old coolant aging and breaking down? or could this mean I have a different brand of coolant in my car?
Keep in my mind it's very hot where I live.
Old on the left, New on the right:
I remember when i bought the car in feb 2021 I could see the coolant's colour in the expansion tank from the outside (don't remember if it was green or blue though), but based on that I would guess that the tank was replaced around that time and a coolant flush was done.