E46XITOE92M3 wrote Why are you running 5w50
Redline 5w50 is equal to the BMW and Castrol 10w60 spec products (RL 10w60 is considered too heavy). Red Line's synthetic oils are ester based which is considered a step up in lubrication and engine protection from the Mobil 1 / liquid moly / castrol / BMW synthetic oils, especially in high revving engine applications. There's a nice little thread somewhere from one of the S65/S85 aftermarket engine builders showing a wear comparison and he advocates for RL 5w50. Here, the metal counts show the 5w50 is performing exceptionally well.
I've got a couple questions in to Pipercross and Red Line.
Update:
Spoke with Pipercross and they confirmed the px1828 is designed for daily driving and that they do run into counterfeit parts on the market. I had purchased mine from an eBay reseller and it's a risk.
Spoke with Red Line and they confirmed that the expected value of silicon in 5w50 is 20 for the additives they use and that because they don't disperse a sample may measure higher. Similar narrative from Blackstone.
I have never liked the design of the air filter and how it essentially presses against the plastic adapter on the engine side of the intake and is sealed and held into place by a spring tension on the edge of the airbox. I decided that 70ish on the silicon was a little too high for my comfort (meaning I felt the risk I was pulling in unfiltered air and dirt was too high ) and purchased a K&N filter as an alternative.
Pulled the airbox and filter mechanism apart this morning and put my hand inside the intake elbow: Grit. No bueno. Cleaned that out and installed the new filter. Was pleased to see the K&N has a different design and snaps into the plastic adapter with a rubbery seal and I think significantly reduces the chance for unfiltered air to get sucked into the intake. Now I wonder if this is the OEM design. Glad I follow my oil reports, this condition could have gone on a lot longer.
Pictures show the dirty towel from the intake, how the Pipercross as purchased simply presses against the intake adapter, and how the K&N fits snugly into the adapter well enough to defy gravity and then some.