Notes indicated silicon could be an additive in the TRIAX. I might have just enough left in the 5 gallon pail for a VOA to check it out. There are no intake leaks that I'm aware of and the air filter is changed every 35K to 40K miles. This fleet vehicle sees almost entirely city/suburban driving and many short trips.
Previous oils used: Havoline Pro DS 5w-20 (3/27/21), Pennzoil Gold 0w-20 (3/2/20), Amsoil XL 10w-30 (11/18/18), Motorcraft Synthetic Blend 5w-20 (2/9/17)
Previous oils used: Havoline Pro DS 5w-20 (3/27/21), Pennzoil Gold 0w-20 (3/2/20), Amsoil XL 10w-30 (11/18/18), Motorcraft Synthetic Blend 5w-20 (2/9/17)