Very interesting set of UOAs!
What stands out for me are the Viscosity, TBN and how they relate to your time and mileage.
Firstly, M1 thinned much more and with less mileage. Blackstone probably said wear and TBN would allow you to run it longer, but it was probably better that you didn't go much below a TBN of 2.5.
Secondly, the magnesium Edge EP held its viscosity well. Though the TBN was high, remember that magnesium oils return higher TBN numbers so again, I wouldn't look at running that oil all the way down to a TBN of 1.
The Ultra then proves why you should not base oil intervals on Blackstone's TBN of 1 is OK. That oil thickened up quite a bit because it starts around 8.3cst and probably thinned first. 11000 miles was way too far even though the TBN was 1.9.
Your newest Edge EP uoa shows only modest thinning but your TBN of 2 is at a point where other, more knowledgeable industry experts would recommend a change.
Since you've described a more robust style of driving, and taking all the UOAs into account, I think the 9000 mile oci with an EP oil, probably Edge, is a prudent maximum.
What stands out for me are the Viscosity, TBN and how they relate to your time and mileage.
Firstly, M1 thinned much more and with less mileage. Blackstone probably said wear and TBN would allow you to run it longer, but it was probably better that you didn't go much below a TBN of 2.5.
Secondly, the magnesium Edge EP held its viscosity well. Though the TBN was high, remember that magnesium oils return higher TBN numbers so again, I wouldn't look at running that oil all the way down to a TBN of 1.
The Ultra then proves why you should not base oil intervals on Blackstone's TBN of 1 is OK. That oil thickened up quite a bit because it starts around 8.3cst and probably thinned first. 11000 miles was way too far even though the TBN was 1.9.
Your newest Edge EP uoa shows only modest thinning but your TBN of 2 is at a point where other, more knowledgeable industry experts would recommend a change.
Since you've described a more robust style of driving, and taking all the UOAs into account, I think the 9000 mile oci with an EP oil, probably Edge, is a prudent maximum.