[cdb95z28]

GM OE pads?
When did you bed them? Given enough street time after bedding, the transfer layer can be wiped off the rotor.
OE pads are a great pad but they can easily be overheated on track with our heavier Gen5s. Even the Gen6 SS 1LEs can overheat the same Ferodo manufactured pads.Throw in the variable of driver braking technique or certain track layouts and they can be inadequate. Your pic shows the pads are starting to smear, which is an indication of overheating. If not already apparent, you may be headed towards vibration from uneven pad deposits. What brake cooling do you have?

5w30 is probably inadequate. I’ve run Mobil 1 Turbo Diesel 5W40 and Mobil 1 5W50. A little more weight is a good thing, but I’m guessing there aren’t too many 90* days in Oregon.