I'm about 500 miles into my first OCI with Rotella T6 5w40 and Bosch filter, about to click over to 100,000 miles on the odo. Just bought the car a few months ago from someone who had dino oil changes at the dealer for the life of the vehicle, had turbo replaced about 15k before I bought the car. Hopefully I can get a UOA done on it within a few weeks. Pulling the banjo filter to check it out next week...