M1 0W30 ESP in 3.6 Pentastar?

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HoosierJeeper

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Have an extra 5qt jug of M1 ESP 0W30 around from my Renegade which I traded in on a JL Wrangler with the 3.6. Did some research and think it should be okay to use over the factory 0W20. Have a trip in September going from WI to Moab for off roading, so thought a little thicker could be okay for the mountains and off roading. What does BITOG think? Run this since I have it or stick with 0W20?

Thanks!
 
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That's what's in my 3.6L JK Rubicon, and if things go as planned it will be going in my 3.6L JL Rubicon, along with a dongle to disable Stop/Start.
 
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I've ran nothing but 5w/30 Mobil 1 in our 3.6 Jeep Grand Cherokee and Ram 5.7 both call for 5w/20. No issues and besides they were originally spec'd for 5w/30 before going 5w/20 for, I think, MPG reasons.
 
It probably won't hurt a thing. BUT....the original Pentastar was specified in some countries with 5w30, so it was designed with that in mind even though 5w20 was specified in the States. However, the PUG Pentastar in your JL is different. It was designed from the outset with 0w20 and that's what was in the crank case for ALL of its durability and validation testing.

I do know this from reading techical articles on it. The journals and passages in the heads and valve train are narrower in diameter than on the original Pentastar. That is where you could run into trouble, eventually. Also I am certain I've read that the ESS feature necessitates 0w20, as well. (I don't use that feature because I think it adds wear and tear, particularly to bearings.)

Anyway, I've rock crawled in Moab in 100 degree temps all day long and into the night on 0w20. No issues. If you are worries about that kind of use, then go with Mobil 1 EP 0w20, which has a good shot of PAO in the base oil. It has more heat tolerance and oxidation resistance than just about anything you'll find on the market, even in 5w30 or 10w30. It is one badass oil. But any good brand of 0w20 will handle anything your Pentastar throws at it.

My 08 3.8 JK was designed for 5w30. I've run mostly 5w20 in it throughout its 14 year life and it has 172k on it now and it runs like new. It was designed originally for 5w30. I've had that JK in every off-road situation you can imagine, again including crawling in 100 degree heat with the air on all day. No issues. Mostly Mobil 1 5w20 over the years.
 
Ran the Pennzoil Euro 0W-30 in my 2020 Gladiator 3.6 Pentastar with no issues. Would not hesitate running the Mobil equivalent either.
 
kschachn said:
Engines may be designed to tolerate thinner oils but that does not preclude the use of a thicker one. You will not "run into trouble" because of narrower passages in the engine or any such thing.
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Are you saying you will run into trouble or have any issue using the 0w20 with which it was designed? And how do you know a thicker oil won't cause trouble in that valve train, eventually? If not, why not 0w40? Or 5w50?
 
IndyFan said:
Why do people think they know better than those who designed the engine?
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The people designing the engines are not the ones saying to use thinner oils. My engine calls for 5W-20 and I am using Mobil 1 ESP 0W-30 and I am using less oil and I feel the engine is running better. The synthetic oils today flow well enough down to 0 degrees that we do not need a thinner oil. I am getting better gas mileage with a slightly thicker oil than a thinner oil, and I do do the same driving and keep track of my mileage.

My parents 3.6 Pentastar owners manual says you can either use 5W-20 or 5W-30

If 0W-20, 5W-20, 0W-30, and 5W-30 all flow the same at 0 degrees and members here have reported using thicker oils with no change in gas mileage then there should be no problem using a thicker oil, unless it is Valvoline or Castrol 20W-50 Dino Oil.
 
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IndyFan said:
Are you saying you will run into trouble or have any issue using the 0w20 with which it was designed? And how do you know a thicker oil won't cause trouble in that valve train, eventually? If not, why not 0w40? Or 5w50?
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Sure why not? It’s not going to hurt the engine. If thicker oils damaged engines then every one would be ruined upon startup. Or for that matter any vehicle operated in the north that routinely does not come up to full operating temperature. The difference between any SAE grade at operating temperature is small compared to any grade at a normal starting temperature. If that 30-grade can’t make it through those small passages at operating temperature then it’s going to grenade at 50F.
 
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Brian123 said:
The people designing the engines are not the ones saying to use thinner oils. My engine calls for 5W-20 and I am using Mobil 1 ESP 0W-30 and I am using less oil and I feel the engine is running better. The synthetic oils today flow well enough down to 0 degrees that we do not need a thinner oil. I am getting better gas mileage with a slightly thicker oil than a thinner oil, and I do do the same driving and keep track of my mileage.

My parents 3.6 Pentastar owners manual says you can either use 5W-20 or 5W-30

If 0W-20, 5W-20, 0W-30, and 5W-30 all flow the same at 0 degrees and members here have reported using thicker oils with no change in gas mileage then there should be no problem using a thicker oil, unless it is Valvoline or Castrol 20W-50 Dino Oil.
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The older Pentastar, sure. The 2018+ JL Jeep has the newer PUG Pentastar (Pentastar Upgrade). It has been significantly redesigned and updated. It specifies 0w20, and nothing else. Even in Europe, Asia, and Australia. 0w20 all the way on this one. Nowhere does it say 5w30 is acceptable. Nor even 5w20. Not on the PUG.
 
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kschachn said:
Sure why not? It’s not going to hurt the engine. If thicker oils damaged engines then every one would be ruined upon startup. Or for that matter any vehicle operated in the north that routinely does not come up to full operating temperature. The difference between any SAE grade at operating temperature is small compared to any grade at a normal starting temperature. If that 30-grade can’t make it through those small passages at operating temperature then it’s going to grenade at 50F.
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Ok, go ahead and run it. If you ever have a valve train issue while under warranty, tell them you were running 5w30 and see what happens.
 
IndyFan said:
Wrong. The 2018+ JL Jeep has the newer PUG Pentastar (Pentastar Upgrade). It has been significantly redesigned and updated.
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My parents car is a 2015, but anyway, you are saying that the new Pentastars are designed in a way that you need to use thinner oils?
 
Brian123 said:
My parents car is a 2015, but anyway, you are saying that the new Pentastars are designed in a way that you need to use thinner oils?
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Yes. The 2015 did indeed allow for 5w30. I think it was even the recommended weight in Europe and other places. But not on the new version. They redesigned the valve train and other components for ESS and for less friction. They went with 0w20 from the outset and it is recommended all over the world.
 
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