My account on getting back to synthetic oil

[BMWDriver]

I've switched back to 5W40 Motul synthetic from regular oil (the previous owner used Castrol GTX regular, and it was due for an oil change).

I'm impressed with two things:

It's been well over 4000 kms since (about 2500 miles), and I still have not had to add a drop of oil, whereas I had to add a liter after 2500 kms of regular oil. I recently checked, dubious, and it's totally full! This engine has close to 400 000 kms (220 000 miles I gather).

It's also right about that time where I should have added coolant, but lo thee, she's still half by the mark beside the radiator.

And do I ever kick the engine, reving up to 5k on a somewhat regular basis.

Love my mechanic.