I have European and exotic auto mechanic shop but I am engineer.I have Mercedes benz and BMW engineering back ground.
BMW got too many oil leak problem from USA consumer.Our research found out a lot of people doesn’t use European formula oil.American formula oil is acidic and when it touches rubber gasket it makes them harder so it starts to leaking
Oil is very important not every oil same.All German manufacture use Liqui Moly in processing but marketing convert them too Mobil1 or Castrol.
We also use CAM2 Blue blood Elite Euro on our customer cars.I recommended this oil
I am from Baton Rouge LA.