Their Euro looks good, but it's likely not good for long drain. It's on the acidic side. However, I have seen some oddball RL UOAs up to near 20k miles that were good so who knows. I would have likely tried Red Line again if had they made their HP Oils with a more modern additive package (lower SA) and retained the PAO/Ester base oil, especially because most engines today are GDI. Their Noack is the best. Always kind of been on the fence with RL. It's great at certain things.
I would say if you kept RL within it's usable limits, engine cleanliness will be as good as it gets. Too far and it won't look as good.
@RDY4WAR said: "Killer base oil blend, as always, but kinda mediocre on the additive package. I guess they wanted to adhere to the SAPS requirements. That Noack is excellent. I would like a higher starting TBN, at least add 300-500 ppm of hard base Mg to get it up to at least 8. That or increase the treat rate of the add pack by 15-20%. This oil likely isn't meant for more than 7,500-10,000 miles anyway, and I'm also looking at it as someone who couldn't care less about emissions requirements."
https://bobistheoilguy.com/forums/threads/how-well-does-redline-oil-clean-engine-varnish.280158/