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Are we in denial about the factory oil viscosity and grade specifications?

JTpanelsOFF

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I used Castrol 0w-40 Euro in my JK. I also used other oils at different viscosities. I bought it new and at ~40k miles, it developed an oil leak. Engine ran and sounded fine. I traded it in for the JT and did not spend time trying to find the source of the oil leak… I think it was the oil cooler but I’m not positive.

We can’t say whether the oil leak was due to the oil selection… I doubt it was but I’m not an expert and do not have statistically significant data to offer.

My JT has gotten dealer oil changes, Pennzoil Ultra Platinum 0w-20 DIY, and Castrol 0w-40 Euro DIY in the summer. No engine concerns or leaks. It has ~28k miles.
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JTDay

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Did somebody say Brotella?

Jeep Gladiator Are we in denial about the factory oil viscosity and grade specifications? 2023-04-21-12-01-50-688


LOL. I used HDEOs in a few of my gas cars in the past. The formulation for T6 changed at least 3 different times in the 8 years I used it.

I use Valvoline EP in my JT now just because.
 

jac04

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My personal preference would be to use an oil which already has sufficient loads of ZDDP, boron, molybdenum, etc, in a simple factory tested formulation --its just easier for me this way.
Agreed. For my old muscle car, I started off using Cam Shield additive, but I quickly switched to Driven Racing Oil HR5 Hot Rod Oil. An oil 'designed' from the get-go with the proper additives is a better choice than worrying about any possible compatibility issues with an additive.

Now, I'm not saying that I buy into the idea of using a high ZDDP oil or a HDDO oil in the JT. I simply agree that using a "factory tested formulation" is better than using an additive.
 
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TheRealStreetcommander

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My JT has gotten dealer oil changes, Pennzoil Ultra Platinum 0w-20 DIY, and Castrol 0w-40 Euro DIY in the summer. No engine concerns or leaks. It has ~28k miles
Awesome. One more data point, and confirmation 40 weight didn't cause phaser or VL issues on yours. Thank you.
 

Maximus Gladius

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This is a site where you’ll get all the info you need on whether or not high ZINC or added ZINC or a thicker viscosity is good for engines. The science is spelled out and with over one million views to this engineer’s site, I’d say his work, tests and opinions are worth the time of day to read.
https://540ratblog.wordpress.com/
 

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sarguy1941

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Note: My solution is to use what the factory recommends and keep fresh oil and filters in all my vehicles. For the JTR, I change the oil and filter before 4K miles, usually at 3.5K miles. I am coming up on my 15th oil change at 56K miles. Motor has been perfect so far. No ticking.

Note: I used The Mopar oil filter which is inexpensive on Amazon, and I used Pennzoil Platinum 0w-20 Synthetic for all the oil changes.
I do the same. Once in a while I'll grab the K&N or the wix but every 3K and am at 68K now with no issues. Our 2009 JK has 180K on it and have done the same since new. We dont drive it alot so now its 3K or 1 year. Think last change had 600 miles on it but makes me feel better changing it anyway.
 

DanW

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The cam and interface damage appears to be a textbook example of insufficient oil film strength. Between the reduction in viscosity and the reduction in friction modifiers in modern xW20 and xW30 oils, are we simply refusing to accept that Jeep has sacrificed longevity for CAFE and questionable catalyst poisoning concerns?

Has anyone actually tried running an xW40 oil, maybe a diesel spec, in their pentastars long term? They have a more substantial additive pack. Not looking for internet lure or personal dogma. Curious if there are any real world forum member experiences with this?
Really? Should I be worried about my 08 JK with 183k miles on it on 5w20 and 0w20?

The truth is that the original Pentastar was designed and met all of its certifications on 5w20. They did spec 5w30 in Europe, but that was for marketing, as Europeans were much slower to adopt 20 weight oils. It was able to meet them on 5w20 when they made the switch to 5w20 for Cafe. The PUG, or Pentastar Upgrade, was designed and tested on 0w20 from the get go.

From talking to one of the engineers, who is a friend, who was on the original Pentastar design team, today's 0w20 synthetic oils have superior base oils and additive packs than yesterday's 30 weight oils. And it has been YEARS since 40 weight oils were used in production passenger car vehicles except for special applications. He will tell you that the 20 weight oils lubricate the valve train better. He advised to run what was recommended, which is 0w20. He said FCA quit giving high mileage badges for high mileage milestones because so many engines were running past 300k miles. Primarily the Pentastar. (The old 3.8 routinely gets past 300k, as well.)

So what does he drive? A 20 teens (2013 to 2015, IIRC) Chrysler 300 with a Pentastar. He runs it hard and it has well over 100k on it.

I was a kid when 10w40 was the most common spec. Those cars rarely made it past 100k, with the exception of some Hondas, Toyotas, and Volvo 240's. But they weren't seen every day.

We've got guys in our Jeep club with Pentastars well past 200k and 3.8's up there, too, in their JK's. My JK 3.8 runs like new at 183k. And there is a famous 625k Pentastar out of a Promaster that ran 5w20 its whole life at 7k oil change intervals. It quit because its timing chain stretched and the guides broke. The bearings and cylinders and crank shaft showed little wear.

I really don't see 20 weight oils being a problem and run them confidently in my Jeeps. A 40 weight probably wouldn't bother the 3.8. It was designed on 5w30. But I'd never run it in a Pentastar. Never.

That's just my 2 cents.
 

DanW

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Here is another truth about oils and CAFE. Carmakers and API adjusted standards to make the new thinner oils perform well. So yes, CAFE was the driver, but the tolerances in engines became tighter and the performance specs demanded by the manufacturers led to API standards that were much tougher. So these thinner oils, when properly certified, peform extremely well in today's engines. Sometimes you can have your cake and eat it too.
 

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Like the very long report cited by @Maximus Gladius said quality lower weight oils perform better in todays engines. However he did say that at about 5000 miles the oil starts to loose it’s lubricating properties and that’s why I’m doing my OCI at 5000 miles regardless of what the computer says.
 

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DanW

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Like the very long report cited by @Maximus Gladius said quality lower weight oils perform better in todays engines. However he did say that at about 5000 miles the oil starts to loose it’s lubricating properties and that’s why I’m doing my OCI at 5000 miles regardless of what the computer says.
I do 5k, too, for margin of safety and error. But that 625k Promaster Pentastar did 7k changes and sometimes up to 9 when he couldn't get it done. He ran mostly Mobil 1 and sometimes Valvoline Advanced Synthetic. All 5w20.

Another note...my friend (the Pentastar design engineer) said all FCA designed engines will meet all performance criteria as low as 1 quart down and up to 1 quart overfilled. Just a nice safety margin of which to be aware.
 

RdFx21

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I have been a lurker of the bobistheoilguy website for quite a while. Reading through many of those discussions (as well as reading through technical write-ups and studies elsewhere) has prompted me to try Mobil 1 FS 0w-40 in my Gladiator as that oil is touted as one with quality base stocks and a strong additive package. In my opinion, the truck has run well the past ~4k miles.
 

whiteglad

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I use old formula CI4+ Delo 400 (15-40) in my race car, along with 1/2 pint old formula EOS. In my Pentastars (Jeep and Pacifica) I use what the factory recommends, 0-20 meeting Chrysler spec MS6395 and nothing else. That way, engine failure is on them.
 
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TheRealStreetcommander

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Really? Should I be worried about my 08 JK with 183k miles on it on 5w20 and 0w20?
I wouldn't. You are clearly not an edge case for your particular engine's follower/arm issues either, and you keep up with your maintenance. The VVL issue is more curious though and more closely similar to the higher pressure flat-tappet cam failures. If a better formulated oil, even if a bit heavier, doesn't hurt operation, doesn't cost any more, and is more resistant to poor maintenance discipline, why not not talk openly about it and give folks an opportunity to make their own decisions? What if it would reduce the edge case failures further?

The warranty concern is mostly a red herring. Unless its 90w, the dealership tech has no idea and doesn't care what he drains from the crankcase. If you are worried, spill and fill it with 20w. Not a show stopper.

I don't think much was proven in 28k miles. Let's see at 100k.
It proves the VVTL oil control systems operate without blatant malfunction on 40 weight, which is a good first step.

as low as 1 quart down and up to 1 quart overfilled.
This is good to hear.
 

Escape.idiocracy

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The cam and interface damage appears to be a textbook example of insufficient oil film strength. Between the reduction in viscosity and the reduction in friction modifiers in modern xW20 and xW30 oils, are we simply refusing to accept that Jeep has sacrificed longevity for CAFE and questionable catalyst poisoning concerns?

Has anyone actually tried running an xW40 oil, maybe a diesel spec, in their pentastars long term? They have a more substantial additive pack. Not looking for internet lure or personal dogma. Curious if there are any real world forum member experiences with this?
Totally different valve train, lower compression etc. ran 0w40 pennzoil ultra platinum in our Jk- zero issues…. When everyone around me was facing passenger side valve rocker issues etc. ours ran quieter, and had zero break downs for the 115k we had it in our possession.

Our jtrd once it’s out of warranty is moving to 0w40 Mobil esp x3.
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