The high temperature that Hemis are set to run at is one of the things that starts a cascading failure. With a 180F thermostat installed and grille shutter delete I went back to Mobil 1 EP 5W-20, and installed a FRAM FS2 filter. She purrs like a kitten. What you see in the picture are typical temperatures for me. I can run cheap gas now as the computer backed down the ignition timing due to lower temperatures. The only reason I ran M1 0W-40 was to compensate for the stupid high temperatures. 210F oil temp was considered low, and at that I had 35psi oil pressure at idle with 0W-40. If you still run the stock thermostat and high temps then run a good ACEA A3/B4 EURO oil. I tried Red Line, but it wasn't for me. At mildly colder temperatures it gets thicker than Mobil 1 FS 5W-40 in my wife's Hyundai. Is PUP bad oil? It's a fuel economy oil full of friction reducers, so I doubt it was the cause. Do you know why Red Lime has so much Moly? So it can cope with the poor friction of some of its base oils. Especially when it gets cold, RedLine oil isn't very slick, but more like molasses. PUP 0W-40 is also a fuel economy oil like the rest of the lineup, but it has more moly to compensate for the higher viscosity and HTHS. A more viscous oil is less slick. They came up with PUP 0W-40 because they needed an oil that can stand up to the stupid high heat that a working truck motor would put out or an SRT vehicles, while maintaining the fuel savings and low SAPS characteristics of an ILSAC oil.
The bottom line is that any oil from a major brand will serve you well. Just try and keep those coolant and oil temperatures in check.
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