Agree with previous post that with current synthetic oils it is unnecessary to deviate from manufacturer's guidance. I do my oil change based on the car notification or when enough time has gone. Sure it is safe to change it more often but I don't find it giving any value.

It's a different story if you have really rough and dirty driving conditions. But normal urban driving you should be fine by following the BMW instructions.

Sure after 20000km it is not the same as new but does the job properly.

In the old old days you did not have to change oil at all. All you did was add oil and change the filter

- p