I hate to tell anyone - but the 6k interval on our 6.4’ and 5.7’ Hemis is about all I can take. Synthetic oil very dirty to the point I want to pull over and change it on the side of the road dirty. “Hemi tick” is there clean oil or synthetic. Run hard and put away wet or baby-ied. I just wish I could get rid of the coolant smell when I shut them off. They all smell like Dexacool dripping on a hot manifold 2 minutes after the engine is off. Yet- no leaks, no loss of coolant. Almost like the pressure cap is “blowing off” pressure.
sorry to side track from engine oil question “OP.”