I recently had a Blackstone analysis done on my Ecoboost F-150. Background: The truck has about 11.5k miles on it. First change was done with Motorcraft semi-synthetic at 1k, second was the Mobil 1 you see in this report at 5k. My plan was to stick with 5k OCIs, but we ended up having to take an unexpected road trip in the truck, so this one got pushed to 6500. I wanted to see how it did with the longer interval, and it seems to be fine. I also don't seem to have as much fuel contamination as I've seen on other Ecoboost engines. Perhaps this is because the sample was taken right after the road trip? I'll be sticking with 5k OCIs in any case, but I thought I'd share and get any comments you might have.