I get 19mpg hammering it with 5W-20. The engine is very responsive now, even more so because of the 180F thermostat and grille shutter delete.
My HEMI is buttery smooth on 5W-20, however, the valvetrain noise is more pronounced when the RPMs are up and there is no load on the engine. Come to think of it, it was more pronounced with the 0W-40 as well before the grille shutter delete and 180F thermostat when the engine was at an operating temperature. In this scenario, 0W-40 is at around 16 to 18 CST most of the time, and that will hide a lot of noise. It doesn't mean that it protects better though. MOFT is a complicated thing and thicker isn't always better. I achieved what I wanted by running the engine cooler by using 0W-40 I'm doubling down on my efforts now, kind of negating some of its benefits. 0W-40 will run about 10F hotter than 5W-20 at the same engine operating temperature of 185, which in turn raises the coolant temp to over 190F at times. So it works against me now. It's either grille shutter delete and cooler thermostat, or thicker oil. Both don't work very well together.
Thank God you didn't buy a Ford. The lifter issue is a materials issue. This isn't something I pulled out of my but. I have someone in my family who is a materials engineer and I talked to him at length about the type of steel to make bearings and other components, and how the automotive business is cutting corners. The fact that it took GM and Ford this long to come around is infuriating. I also discussed this issue with others who had a more objective view on this issue, and the consensus is that it's a materials issue. Also, idling this motor with 5W-20 when the oil temp is at 220F or above is not that great of an idea as MOFT might not be maintained between the camshaft and roller lifter. This issue is not as simple as "throw some RedLine at it." Or just run a thicker oil. If you made it this far and your engine is running fine then you're okay. And if you don't want to touch the thermostat then keep running 0W-40, it will serve you well. I effectively modified how the ECM interprets the engines operating temperature and I found out that it's reaching its maximum efficiency now while running 5W-20. The only issue you might one day run in is exhaust manifold bolts due to the high temperatures.
I think that the noise on the passenger side is coming from the catalytic convertor. It doesn't sound like a piston slap or lifters. These HEMIs make so many noises that they can make people paranoid. I need to go under the truck with it running and use my stethoscope to listen to the catalytic convertor. It's not the exhaust manifolds, they look clean and seal well. I crawled and checked everywhere.
The manifolds can be replaced with shorty headers with grade 8 bolts which can hook up to the existing catalytic converters. They will also provide a boost in low-end torque without altering emissions. That's what I'm going for. Or I could always install the headers from the 6.4 HEMI.
The Hemis have one built-in. The 5.7 expects to find 5W-20 and the 6.4 expects to find 0W-40. By running RL 5W-30 your truck thinks that it's 0W-40 since they are very close. It's easy to detect viscosity for an ECM and they could even warn the driver if the oil viscosity is too low and MOFT is not maintained, but why would they? The HEMI has a variable oil pump. The only difference I get in oil pressure is at idle. It's lower at idle now than it was with the 0W-40. As soon as I touch the throttle is up there, and with the bigger oil filter, it's even livelier than before. Think about it this way: At 200F more 5W-20 will flow than 0W-40 at 1500 RPM because the engine is maintaining the same 53 PSI. And it knows, because if the oil pump wasn't variable, then I would have two different oil pressures with two different oils at the same RPM.
The only reason I can think of that Chrysler might back down the engine efficiency with a thicker oil for the RAM 1500 is because they designed it as a half-ton truck. They already run it incredibly hot, probably for the same reason: they don't want people to use it for any kind of heavy-duty work. Instead, those who want a better truck should buy 2500/3500 or bigger. They do the same thing with the ZF transmission in the RAM 1500 by running it at some crazy temperatures. What do you think?
My comment about people paying $60K for a middle of the roam RAM 1500 was not targeted at you. That's about how much a Big Horn equipped like mine costs now which is ridiculous. My truck with sunroof, 4WD, 5.7 HEMI, 8 Speed, trailer brake, climate control, 7-inch EVIC, 8.4 U-Connect, the middle console was $35K in June 2016. We might have inflation, but such a price hike is ridiculous. Nothing will change until people stop borrowing money to pay stupid prices like that for a light-duty truck. If it was at least a 2500 or 3500 that's well equipped then I would understand. But not this. Even the Chevy Silverado with the puny 2.7L Turbo 4 cylinder went from $32K to $45K in less than a year. Hurray for the banks, what can I say?
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@Travis8352 Castrol 0W-30 is made in Belgium now, it's hard to get and expensive and a hair thinner than the 0W-40 you can find at Walmart. So why bother? There is a reason why no one wants to make ACEA A3/B4 0W-30: because they can't get it past API SL so very few vehicles need it.
RedLine 5W-20 would probably be an excellent option for me now. I get oil that won't shear, it would be in the viscosity that the HEMI likes and it has all that Moly goodness and ZDDP that's so good for the engine. But it's so expensive!