Originally Posted by racin4ds
Oh so many folks have seen this over the past several years and it also shows up as increased noise, rattles and other obvious signs the oil is not doing its job. This is why I vowed to never use an M1 product again. I gave it the benefit of the doubt and tried it years ago in 3 different vehicles and got the same, poor results and my father- a long time Mobil user also stopped using it when his Brand new 2016 Civic began ticking and rattling on startup. All noises went away upon switching to Pennzoil oils.
Sure, but let's not get ahead of ourselves and reach to conclusions here and bash one oil against another. Moreover, that infuriates people.
M1 and PP are both great oils, each with strengths and shortcomings.
Regarding high iron, it was more a problem in the SM days; so, it could have to do with the base-stocks types back then, such as generous use of esters perhaps, which is not the case today.
The thinner base oil only applies to M1 5W-30 flavors. Other M1 SAE viscosities are fine. If there is no wear issue in an engine, 10 ppm vs. 15 ppm iron won't make much difference. If the engine wears badly, then one can experiment with different oils and find something with a thicker base oil, even a 10W-30 or 15W-40 instead of a 5W-30.
Regarding noise, it's almost entirely subjective and doesn't mean anything.
The PAO-and-AN-based M1 EP 0W-20 SN PLUS is absolutely the best oil by far I have run in my engine in terms of how it sounds and feels, even though that sounds subjective as well. We will see how the UOA will also be good or not.