5W-20, 0W-20 or 5W-30 for 3.6L Pentastar (Jeep)

[PontiacHO]

Y’all win. When efforts to rectify a problem and drawing similar conclusions among professional fleet managers is regarded as lunacy based on a moon phase and/or feelings then my 40+ years in the industry was just dumb luck I guess. Working in the confines of fixed budgets and key performance measures creates the need to become open to new products etc., regardless of what a data sheet may contain. Some products work and some don’t. I admit I don’t have the background and education to discern why. All I know is what was tried and worked for the municipalities in the Carolinas. Maybe it’s not a moon phase but regional?? Bull shift…

 

[IndyFan]

And is most always the case, "real world" or "field" data does not have anywhere near the relevance people think it has. It's always based on perception and anecdotes which are highly subjective. The ugly truth that is often hard to understand is that it's nearly impossible to draw any real conclusions outside of a laboratory where multiple and significant variables can be controlled.

Illusory correlation:



https://www.scientificamerican.com/article/lunacy-and-the-full-moon/

Yes, but there is often variance between lab results and the field. The sample size of the field is much greater and subtleties in usage pattern variance isn´t always predicted in the lab. Both are valuable sources of data, IMO.

¨God help us! We are in the hands of engineers." Ian Malcolm

Debate away on the älleged design flaw..., quality issue, or materials flaw...or whatever it may be. Most of them don´t have this failure. Fact is, this engine has one of the lowest warranty cost claim rates in the industry, which is why it is still so widely used across the Stellantis product line. The fact is that most of them are run on the factory specified oil weight and they are well known for longevity with many, many very high mileage examples on the road every day.

I think these engines do just fine on 20wt oil. Just as millions of other engines do. I had a 2002 Ford F150 with a 5.4 and all it got was 5w20. I sold it to a friend. It has over 200k on it now and he continued the Mobil 1/Fram or Motorcraft regimine that I had used. I towed big boats with that thing, many times. I believe good cooling system maintenance contributes to it, along with other basic and sound maintenance practices.

 

[CarbonSteel]

Yes, but there is often variance between lab results and the field. The sample size of the field is much greater and subtleties in usage pattern variance isn´t always predicted in the lab. Both are valuable sources of data, IMO.

¨God help us! We are in the hands of engineers." Ian Malcolm

Debate away on the älleged design flaw..., quality issue, or materials flaw...or whatever it may be. Most of them don´t have this failure. Fact is, this engine has one of the lowest warranty cost claim rates in the industry, which is why it is still so widely used across the Stellantis product line. The fact is that most of them are run on the factory specified oil weight and they are well known for longevity with many, many very high mileage examples on the road every day.

I think these engines do just fine on 20wt oil. Just as millions of other engines do. I had a 2002 Ford F150 with a 5.4 and all it got was 5w20. I sold it to a friend. It has over 200k on it now and he continued the Mobil 1/Fram or Motorcraft regimine that I had used. I towed big boats with that thing, many times. I believe good cooling system maintenance contributes to it, along with other basic and sound maintenance practices.

Not my experience. Oil cooler leaking at 50K miles and a coolant leak that was either a head gasket or cracked head/block. Changing the oil cooler did not solve it. Color me unimpressed with the 3.6L engine and FCA's design skills...

For xW-20 oil, I think it depends on the power density of the engine. As you said, there are plenty of engines that run just fine on it and others that don't/can't.

No oil viscosity is a one size fits all...

 

[EBruce]

I was told not to run 5-30 synthetic and to use 0-20 syn. My mechanic said that it will cause cam phaser issues. I find that hard to believe as this 2019 motor sold in other countries can use 5-30. I am out of warranty and want to try it but for now went to 5-20 Mobil 1 to see if it makes a temp or pressure differance on the oil. There's a ton of threads on this and it becomes confusing on what I can do although I
think 5-30 will be ok.

 

[kschachn]

I was told not to run 5-30 synthetic and to use 0-20 syn. My mechanic said that it will cause cam phaser issues. I find that hard to believe as this 2019 motor sold in other countries can use 5-30. I am out of warranty and want to try it but for now went to 5-20 Mobil 1 to see if it makes a temp or pressure differance on the oil. There's a ton of threads on this and it becomes confusing on what I can do although I
think 5-30 will be ok.

First off, synthetic or not that has no relevance. Neither does the winter rating in this instance.

If it has "cam phaser issues" just because you increased the 20-grade to a 30-grade then it must have all sorts of issues any time the oil is not at operating temperature. Otherwise the 20-grade is essentially as overly thick as the 30-grade. Here in the upper Midwest, many engines never reach normal operating temperature in the winter. Somehow these vehicles don't have issues. There is a lot of misinformation out there on oil, especially on grade.

 

[IndyFan]

I was told not to run 5-30 synthetic and to use 0-20 syn. My mechanic said that it will cause cam phaser issues. I find that hard to believe as this 2019 motor sold in other countries can use 5-30. I am out of warranty and want to try it but for now went to 5-20 Mobil 1 to see if it makes a temp or pressure differance on the oil. There's a ton of threads on this and it becomes confusing on what I can do although I
think 5-30 will be ok.

That is all mechanic baloney. First of all, the newest version of the Pentastar (the PUG) specifies 0w20 from Europe to Australia and even in the Middle East. It was designed and developed, tested and validated, on 0w20.

Run what the manufacturer specifies and feel good about it. Then again, you can run that 5w30 and I doubt it will ever do any harm.

Do a search and see what @OIL_UDDER had to say about Pentastars and oil. He was on the design team on the gen 1.

 

[demarpaint]

I was told not to run 5-30 synthetic and to use 0-20 syn. My mechanic said that it will cause cam phaser issues. I find that hard to believe as this 2019 motor sold in other countries can use 5-30. I am out of warranty and want to try it but for now went to 5-20 Mobil 1 to see if it makes a temp or pressure differance on the oil. There's a ton of threads on this and it becomes confusing on what I can do although I
think 5-30 will be ok.

I'd find another mechanic. I'm running either 0W30 or 5W30 ESP in mine, w/o issues. My bet is there are over a million people running XW30 or XW40 grade oils in that engine w/o issues, considering the fact that there were well over 12,000,000 of those engines made last count I saw a few years ago.

 

[CarbonSteel]

Run from that idiot like the plague. I have personally ran 0W-20, 0W-30, 5W-30, and 0W-40 in a 2019 Jeep Wrangler with ZERO difference in operability. I have a friend in TX who bought his just before mine and has ran 0W-40 from the first oil change and had upwards of 130K hard miles on it.

Contrary to what is typically parroted on forums, the 3.6L is NOT viscosity sensitive and given that all oil passages and clearances are the same as earlier 3.6L models, it is a stretch to say it was designed for xW-20.

 

[kschachn]

Contrary to what is typically parroted on forums, the 3.6L is NOT viscosity sensitive and given that all oil passages and clearances are the same as earlier 3.6L models, it is a stretch to say it was designed for xW-20.

Plus the fact that “passages and clearances” have nothing to do with it.

 

[Glenda W.]

I was told not to run 5-30 synthetic and to use 0-20 syn. My mechanic said that it will cause cam phaser issues. I find that hard to believe as this 2019 motor sold in other countries can use 5-30. I am out of warranty and want to try it but for now went to 5-20 Mobil 1 to see if it makes a temp or pressure differance on the oil. There's a ton of threads on this and it becomes confusing on what I can do although I
think 5-30 will be ok.

Sounds like you know more than your “mechanic”. The old cam phaser sensitivity myth is as just as bad as oil passages being to small. 5w30 is perfectly fine.

 

[1blkc5]

I have been running 10w-30 but I'm in Florida

 

[wemay]

Data collection based on laboratory and controlled field studies only tell you so much.

Data collection based on real world experience is necessary to validate the lab and controlled studies further.

If this weren't the case, design flaws, which failed to rear their heads during the engineering/testing phase of anything manufactured, wouldn't exist. Be that motor oils or engines.

The conundrum lies in where to attribute these failers.

 

[Sandstorm]

Data collection based on laboratory and controlled field studies only tell you so much.

Data collection based on real world experience is necessary to validate the lab and controlled studies further.

If this weren't the case, design flaws, which failed to rear their heads during the engineering/testing phase of anything manufactured, wouldn't exist. Be that motor oils or engines.

The conundrum lies in where to attribute these failers.

Many companies conduct field testing in addition to the bench tests that are conducted in the lab.

 

[kschachn]

Data collection based on laboratory and controlled field studies only tell you so much.

Data collection based on real world experience is necessary to validate the lab and controlled studies further.

If this weren't the case, design flaws, which failed to rear their heads during the engineering/testing phase of anything manufactured, wouldn't exist. Be that motor oils or engines.

The conundrum lies in where to attribute these failers.

The reason one may find a conundrum is because what really matters is the statistical analysis of any results, whether they be from a laboratory test or a field study. One can spend enormous amounts of money, generate reams of data, and think you see a trend, all to find it has zero relevance whatsoever. This is what makes standardized tests important. You have to do your own analysis on any other type of test, and that is nearly always skipped.

 

[KrisZ]

For Texas heat 5w30 is probably a good idea, but if you’re doing it to save the rockers specifically, you won’t. Oil viscosity has nothing to do with these failures.
I’ve run 5w30 in my Grand Caravan ever since I dumped the factory fill at around 600 miles. My rockers failed at around 90k mile mark.

 

[BillyTheKid]

I ran super tech 10k rated 10w30 synthetic in a 3.6 for just about 15k miles with outstanding uoa results. This was in NYC area and mixed driving with also a good amount of e85 run through it.

 

[IndyFan]

Run from that idiot like the plague. I have personally ran 0W-20, 0W-30, 5W-30, and 0W-40 in a 2019 Jeep Wrangler with ZERO difference in operability. I have a friend in TX who bought his just before mine and has ran 0W-40 from the first oil change and had upwards of 130K hard miles on it.

Contrary to what is typically parroted on forums, the 3.6L is NOT viscosity sensitive and given that all oil passages and clearances are the same as earlier 3.6L models, it is a stretch to say it was designed for xW-20.

Not at all a stretch. This was from Kevin @OIL_UDDER, who designed the original gen 1. He said the PUG has extensive re-working of the cams/valve train with the primary goal being to reduce friction, improving efficiency. So it is not at all a stretch to say that. He said it. He knows the team who designed the PUG.

I'm not saying 5w30 would hurt it, but he recommended 0w20 and explained why in detail. IIRC, he also had something to say about the timing chain and an advantage there, too, for 20 weight.

I don't think he said 5w30 would cause any problem. He was just talking optimization from the perspective of a Pentastar design engineer.

 

[CarbonSteel]

Not at all a stretch. This was from Kevin @OIL_UDDER, who designed the original gen 1. He said the PUG has extensive re-working of the cams/valve train with the primary goal being to reduce friction, improving efficiency. So it is not at all a stretch to say that. He said it. He knows the team who designed the PUG.

I'm not saying 5w30 would hurt it, but he recommended 0w20 and explained why in detail. IIRC, he also had something to say about the timing chain and an advantage there, too, for 20 weight.

I don't think he said 5w30 would cause any problem. He was just talking optimization from the perspective of a Pentastar design engineer.

He also aired many words of caution and how the PUG engineers were very concerned about using xW-20 in it. There is nothing, I repeat nothing in a 3.6L PUG that requires xW-20. The oil passages, clearances, tolerances, timing chain systems, and the like are EXACTLY the same as previous 3.6L engines. The VVT system is electronically operated and does not rely on oil pressure or oil viscosity to function--just like the previous versions that did not use xW-20. In addition, the oil recommendation in a PUG from Jeep is a RECOMMENDATION and not a REQUIREMENT, so yeah. it's a stretch.

Clearly if the PUG was "designed" for xW-20, then 0W-40 should cause issues and it does not. There is only ONE reason that Jeep:

- reduced oil viscosity in the engine from xW-30 to xW-20
- reduced the weight of the engine
- installed aluminum suspension components
- went outside of Dana's specifications for the axle oil viscosity by reducing from 75W-140 to 75W-90
- reduced the oil capacity in the engine and the axles
- replaced the 5 speed automatic with an 8 speed automatic
- increased the use of plastics in the powertrain and body
- installed a front axle disconnect
- replaced steel body panels with aluminum
- installed a start/stop system

and that is MPG requirements for CAFE to meet the required numbers.

 

[IndyFan]

He also aired many words of caution and how the PUG engineers were very concerned about using xW-20 in it. There is nothing, I repeat nothing in a 3.6L PUG that requires xW-20. The oil passages, clearances, tolerances, timing chain systems, and the like are EXACTLY the same as previous 3.6L engines. The VVT system is electronically operated and does not rely on oil pressure or oil viscosity to function--just like the previous versions that did not use xW-20. In addition, the oil recommendation in a PUG from Jeep is a RECOMMENDATION and not a REQUIREMENT, so yeah. it's a stretch.

Clearly if the PUG was "designed" for xW-20, then 0W-40 should cause issues and it does not. There is only ONE reason that Jeep:

- reduced oil viscosity in the engine from xW-30 to xW-20
- reduced the weight of the engine
- installed aluminum suspension components
- went outside of Dana's specifications for the axle oil viscosity by reducing from 75W-140 to 75W-90
- reduced the oil capacity in the engine and the axles
- replaced the 5 speed automatic with an 8 speed automatic
- increased the use of plastics in the powertrain and body
- installed a front axle disconnect
- replaced steel body panels with aluminum
- installed a start/stop system

and that is MPG requirements for CAFE to meet the required numbers.

Again. I never said or believed it was a problem to run 5w30. Only that 0w20 is just fine. He told me directly that he runs 5w20 in his 300 with no concerns. I don't remember him telling me anything of the concerns. And I have none. I do remember him telling me directly about 0w20 being advantageous in the PUG's valve train and timing chain. I think I remember him posting that stuff, too.

Run the 30wt and be happy. It's a Pentastar. It'll go the distance.

I don't see Pentastars wearing out in these parts. Almost universally they run 20wt bulk oil. THe few problems I've seen are not oil related.

You'll find this fun...my best buddy has a gen 1 Pentastar and he chokes it with a quart of Lucas oil stabilizer at every OCI, which I'm not sure he bothers to do sooner than 15k or so, when he feels like it. What's that crap, like 120 weight? His engine runs fine. But it brings tears to my eyes when he pours that $h** in there. So I think we are all spending a lot of energy yakking about NOTHING. LOL.

Have a happy Thanksgiving, buddy. It is good to hear from you!

 

[CarbonSteel]

Again. I never said or believed it was a problem to run 5w30. Only that 0w20 is just fine. He told me directly that he runs 5w20 in his 300 with no concerns. I don't remember him telling me anything of the concerns. And I have none. I do remember him telling me directly about 0w20 being advantageous in the PUG's valve train and timing chain. I think I remember him posting that stuff, too.

Run the 30wt and be happy. It's a Pentastar. It'll go the distance.

I don't see Pentastars wearing out in these parts. Almost universally they run 20wt bulk oil. THe few problems I've seen are not oil related.

You'll find this fun...my best buddy has a gen 1 Pentastar and he chokes it with a quart of Lucas oil stabilizer at every OCI, which I'm not sure he bothers to do sooner than 15k or so, when he feels like it. What's that crap, like 120 weight? His engine runs fine. But it brings tears to my eyes when he pours that $h** in there. So I think we are all spending a lot of energy yakking about NOTHING. LOL.

Have a happy Thanksgiving, buddy. It is good to hear from you!

No harm, no foul, but I do struggle with his statement of "0w20 being advantageous in the PUG's valve train and timing chain". Many PUGs have failures in the valvetrain system (the JL forum is riddled with them) and while more likely due to the garbage design than the oil, I do not see how 0W-20 is helping either.

Mine developed a cracked head or block around 50K miles and worsened until I dumped it a little over 70K and while no fault of the oil, it highlights the design issues this engine has. The JL forums are starting to have quite a few posts about cracked heads, blocks, or blown head gaskets and valvetrain issues are easy to find there as well--again, likely due to design versus any magic elixir from a bottle.

Happy Thanksgiving!