Reason I'm asking is my service book says first change of tranny oil should be at 120k kilometers (~75k miles) or in rough conditions on every 60k kilometers (~37k miles). Comparing these two intervals I'm sure I belong to 120k group since I make around 70 kilometers (~45 miles) per day more or less in 5th gear at 80 km/h (50 miles/hour).
However I'd also like to make sure oil wouldn't be the problem in case of transmission failure so I checked on this forum and saw some guys recommend changing oil every 15k (I think it was in miles) if driving hard or 35k (miles) if driving like a granny.
I got scared and I booked a service just to change tranny oil
About oil chaning procedure I was told to first get rid off old oil get a new one in (about 3,5 liters) take the car for a spin (it's enough to fully warm up the engine) and repeat procedure once again.