Hoot: if you were running the SRT 0W-40.
There is a good chance the 5W-30 that you are running now has a more Robust additive package compared to the SRT 0W-40. It is one of the weakest of the 0W-40 group. Only thing it has going for it is the Moly. It has shown through a few posted UOA to shear fairly quick. **** before it is even poured in it is boarder line 30Wt.
This might be a different case if your Ram Truck 6.4L was only used for daily casual driving & never really worked hard. The SRT 0W-40 might stay in grade for much longer (Might). If towing heavy & often well that changes many things.
Is it just the Cam & Timing that is different between the Ram 6.4L & the Challenger/Charger 6.4L motor?
Found some of it:
New for 2014 was a specially designed 6.4 liter Hemi V8 specially created for heavy duty Ram trucks. Despite the identical size, they are very unlike the 6.4 liter SRT Hemis, rated 470 hp and 470 lb-ft.
The engine was redesigned for durability, torque, and economy with heavy loads; it runs on 89 octane gas and is matched to a six-speed automatic transmission only.
For trucks, durability and a broad torque curve take priority over horsepower, so (taking cues from Mopar engines of the distant past) the designers used sodium-filled exhaust valves and tougher valve seat materials, with aircraft-grade stainless steel exhaust gaskets and fasteners, and oil jets for cooling the pistons. A high-volume oil cooler and revised PCV system increase oil efficiency, while computational fluid dynamics optimized the cooling circuit.
Maybe this motor is just naturally harder on the oil? I honesty can't see that being the case. Maybe Ram is actually acknowledging the importance of Film Strength? Hmmm!
M1 FS 0W-40 is supposedly in the same boat it seems. Since it is supposedly produced using the (GTL) process as well. Which makes its base oil much thinner then the past versions. Good thing is the additive package is still strong.
