Fuel dilution?SupraSteve
Since you're not looking for extended drain intervals and are content with 10k kilometer uoa's, I would switch to some different brands of synthetic. These Ecoboost motors are known for shearing Oil out of Grade. Your 2.7L EB was no exception. I'd like to see what Amsoil SS, High Performance Lubricant, and Super Tech would do head to head
We saw what M1 did
Best of luck