How much Lucas oil additive is too much

I have a cat c15 MBN tuned to a 550 6nz . I run my intervals typically around 20,000. I notice my oil gets rather thin or is consumed faster I add about a gallon of Lucas. It bumps up my oil pressure and slows down the oil consumption. This oil change has been a hard one been up and down mountains averaging 5.2. I have added around 3 gallons of Lucas and 1 gallon of 15w40. If I had to guess I think it’s about perfect. Any input?

 

Also added around 10,000
20,000
And 28,000 miles on change.

 

The guy before me did a crap job with maintenance so I’ve been testing out additives and oil stabilizers rather diligently.I can tell you fuel stabilizers seem like I joke to me. Oil stabilizer by Lucas seems proficient.

 

Most of my oil gets consumed. Or gets running so as it breaks down wouldn’t Lucas bump it up. It’s not like I added 3 gallons at once. Just curious.

 

Or drips out/ runny

 

I only do it when I smell my oil worse than I do before. Or when it gets runny or my low idle oil pressure drops below 50 psi. It usually keeps it at 70psi. Idk I have heard good and bad. Guess all I can say is this is a good test motor so to say lol.

 

60 psi is what it keeps it at sorry not 70

 

I’ve been running proguard 15-40 conventional but I’m thinking about switching. Best oil for c15?