Is it still the prevailing thought that intake carbon buildup comes a lot from NOACK properties of an oil?
About to get my intake valves walnut blasted on my Macan S (128k mi, V6 twin turbo), I mostly use M1 0w40 FS. Will probably just stick with that and 5k intervals (filter 10k). But I'm curious if there's a diff oil I should consider that's A40 or as good as A40 and has lower NOACK.
Noack on 1 hand, exhaust gas reversion on the other. I'm going with a no VII, ester containing oil in my DI engines anyway. 10W-30 to be precise. I could likely get away with a 20W-xx even in the coldest of winter, so 10W-30 allows the winter grade to slip and still be more than adequate.