I was careful to say spec, and not grade. All of us around here chasing "better" oil specs for our motors, bigger/better filters, etc.
I know, tinfoilhat time.
Hemi oil weight, is it really that sensitive?
- Thread starter KrisZ
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I know, tinfoilhat time.
It may not be long though. If increased incentives (or worse, requirements) are offered for a mechanical or electronic nannying system then it will happen. Dire owner’s manual statements and requirements for marketing and supply chain assurance will become inadequate.
My truck sits at 30-33psi hot idle.
With a fresh oil change and Mopar filter, 29-30 psi.
After some miles, especially with a high efficiency filter, low 20's. Using a well-flowing filter that isn't too efficient is quite important on these engines.
There have been numerous examples of loaded, high-efficiency filters causing oil pressure issues on these engines....which have resulted in a P1521 fault. Amsoil has a bulletin out on this as well.
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Here is mine, running HPL PCMO 5w-20 after a 30 minute trip to the city and back. I never see < 40 psi anymore, not even in the summer while towing. Temps don't go past 100 either unless its towing.
My PSI seems to hold steady regardless of oil weight, I've run 5w-30 no vii and it was similar numbers.
My PSI seems to hold steady regardless of oil weight, I've run 5w-30 no vii and it was similar numbers.
OVERKILL
$100 Site Donor 2021
That's wild, I've never seen anywhere near that low, and I run high efficiency filters exclusively. That said, we do know this engine is notoriously dirty running and produces lots of particulate and I am not a fan of the downsized filter, hence using the larger SRT-spec'd filter.
That's because your oil temp is only 88c (190f). I typically see 210-220f. Once you get above 210f, the pressure drops to about around 30 psi.
They will throw a notifier code (P1521) based on oil pressure relative to oil temp on anything other than 5w20. This will not set a check engine light. I've run 0w40 and up to 15w50 in 5.7ls both eagle and pre eagle without issue. They will be happy with pretty much anything you put in there.
Make your pick of any xw20/xw30/xw40.
Make your pick of any xw20/xw30/xw40.
OVERKILL
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Not to nitpick, but it can't, the system can't be that sensitive, because even within the xW-20 grade, there is a considerable range. Factor in different engine states of wear, build variation and other influences and there's simply no way it can be. Some of the 5W-30/0W-30 oils are within spitting distance of the visc for some of the xW-20's. Any of the API ILSAC oils with the HTHS around 3-3.1cP aren't going to make enough of a difference in visc to throw the inferred "visc out of spec" flag.
I suspect the same would be the case for a 0W-16. Depending on where the oil falls on that range, would influence whether it sets the flag or not. Not that I'd ever run, or recommend somebody run 0W-16 in a HEMI.
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I will keep an eye on it. I know for sure I haven't seen < 40 psi at idle for over 4 years, including many hot summer towing days reaching 105 to 110, that's usually on xw-30.
This oil change was an anomaly in that I usually never run 5w-20. I haven't seen > 95 degrees with this oil as it was changed right before winter so I can't be certain what it does in the hot summer.
Using HPL premium plus 5w30 at 224f i still had 36-37 psi
That’s a pretty significant difference. I have only ran many brands of xW-20, and have NEVER seen above 30psi at that oil temp.
So, it may not be that difficult to detect a xW-30 being used…
OVERKILL
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I mean, I was 32psi at 219F with the SC 0W-20, HTHS of 2.74cP, which isn't far off. The No VII Euro 5W-20 has an HTHS of 3.27cP, which is higher than most ILSAC 5W-30's.
I was looking through the Chilton Repair Manuals specifically for information on this issue, and it appears the P1521 DTC is no longer listed as an available code for 5.7 Charger, Challenger and Durango models built after MY 2020. I’ve owned vehicles with both 5.7 and 6.4 hemi engines, and while the 5.7’s were quiet, the 6.4 had a horrendous tick, even on Redline 0W40.
That’s a massively poor design if it did.
OVERKILL
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Another data point with some "aged" HPL SC 0W-20:
4WD
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Just donated 3 jugs PP 5W30 to a brand new 5.7L Hemi with the eTorque feature …
I ran a couple 5w20s and mostly saw 32-33 psi. M1 FS 0w40 was around 41-42 psi at 212f i ran that oil for a long time. I ran HPL supercar 0w30 and that ran at 39 psi at the same temp
I’ll take a pic for everyone during my next drive. It has a fill of HPL No VII 5W20 with 1600 miles and a Mopar Oil Filter.
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