Now that's what I call a good data stream!
Congratulations! You are one of the VERY FEW BITOGers that can say you have "real" data.
You need about 5 more to be statistically viable; takes 30 samples minimum to understand normal variation.
Keep on it!
The act of preventative maintenance, in and of itself, is FAR MORE important than brand/grade/base choices among lubes and filters.
- under maintaining something is akin to abuse/neglect; that can kill equipment by shortening the lifespan
- over maintaining something has never been proven to be anything but a waste of time and money