Hello! I just had to change the cooler of my S80 and of course also the oil of the transmission oil oil cooler came to me (automatic gearbox). This was quite black (the color, which also has the normal oil, when you make an oil change). Now I had to fill in some (0,5l) fresh automatic transmission oil (AW55-50), which I bought directly from Volvo. The color of the new oil is red. Now my question: I know that Volvo does not prescribe a transmission oil change, and I know that in the 850s series there have been massive problems with this regulation, but now there is no need for it. But should I still make a change? Or is the color (which is caused by suspended substances) irrelevant? What do you mean? Change: Yes or No? Thank you for the comments MedanoCC