Oil choice and carbon-build up (Petrol Engine, N53/N54/N55)

Hi,



I am about to change oil in my E91 330i (N53).



One of my concern is to prevent carbon build-up in the intake as much as possible. From what I understand, the build-up is mainly due to a mix of fuel and oil vapor creeping up in the intake. So in order to minimize it, Oil should be low SAPS/ash and low volatility (high flash point ?), shouldn't it?



There are 2 LL-04 oil I would like to choose from (I live in France) :



Mobil 1 ESP 5W30 (link)



Castrol Edge 0W40 (link)



I have been using the castrol edge so far and I was happy about it but I might as well give a try to the mobil since it has even lower ash content and a highest flashpoint but it has a narrower grade span...can't decide really.



Any piece of advice is appreciated !



Thanks!