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

[TheRealStreetcommander]

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?

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[sharpsicle]

Not looking for internet lure or personal dogma. Curious if there are any real world forum member experiences with this?

Man, that's exactly what you're going to get though. "Real world experiences" are just anecdotal evidence that, once written down here, becomes "internet lore". I mean after all, you started your post with statements based on assumptions based on that very "internet lore or personal dogma" you want to avoid.

You're better bet here is to statistically show there is a problem with using the Jeep recommended oil weight, then do sample size experiments with other oil weights and perform an analysis of the results in order to determine if there is actually an impact with the change. And it's difficult to get enough of a sample size to actually get enough data. You can't do it on one engine. Without that, it's all speculation. Perhaps really good sounding speculation, but speculation nonetheless.

Sadly nobody actually does this, not even a token attempt at gathering any real population data, and these threads are always destined to become absolute garbage. You only get one-off answers, for one case, which isn't representative of the whole. And without proper DOE and statistical analysis, there's absolutely no way to know if other variables are at play, what are outliers, and what the real truth is. That is to say, any conclusions are unreliable.

Can't reject the null hypothesis. Can't reject that the factory oil is sufficient.

Typically these conversations show that running a different oil is a solution looking for a problem that doesn't exist, all based on what someone "thinks" or "feels" or "believes". Not based on actual numbers. After all, your post itself is based on your "feeling". You're free to do what you want, based on your own preferences and beliefs, but if you think you'll get fact from other's preferences and beliefs, you're gonna have a bad time.

 

[TheRealStreetcommander]

Corporate Average Fuel Economy. AKA Draconian government legislation that forces automakers to build trashier, less durable, and more dangerous automobiles, for the purpose of improving fuel economy/reducing emissions.

I and all my family have also used HD diesel oil in all our gas autos since the late 90s. Never had a problem, and never had an oil or cat related issue.

I'd like to be sure there haven't been any actual negative experiences from use of HDDO in a Pentastar. First-person experiences. And, curious if there are some people who use HDDO with great results, but are afraid to say it on this forum.

 

[TheRealStreetcommander]

This one peaks my interest. I used to run T4 in my Goldwing, and I used their Gas Truck oil in my JK. Always been a Rotella fan.
https://rotella.shell.com/en_us/pro...-vehicle-5w-30-full-synthetic-heavy-duty.html

Yes, good eye. It peaked mine as well. My first OC will probably be this Rotella or a euro-spec 0w40.
Maybe I'll even go for my bawls and commit with Rotella 5w40. We'll see how I feel at the time.

 

[smlobx]

What @sharpsicle said is very true. I built a home in VA for the head of a company that makes the additive package for many major oil brands and the amount of work to get definitive proof of how an oil package works costs several million dollars, not something anyone here can afford to do.

I also have several diesel vehicles and have been using Rotella T6 in them (and others) for decades. I feel it is the best diesel oil available.

For my Jeep I just do OCI every 5K miles regardless of what the computer says and sleep very well at night. Where I live in NC we don’t get extremely hot weather or have big mountains so I don’t think we stress our Jeeps too much. If I was routinely towing a trailer in 100 degree heat for long distances I “might” consider a 5w-30 but I have no empirical data to back it up.

One last note, in my Porsche race car that we did use in very high summer temps at 5-7K rpm’s I did run M1 15W-50 oil but that was a very high stressed motor and not a street engine.

 

[Rahkmalla]

regardless of what the computer says

You know you don't HAVE to trust computers. Blackstone Labratories are readily available to test your oil and recommend an oil change interval for you. I changed at 1k, 7.5k, and 14k and just sent my 14k oil off for analysis (which i plan to do every 2 oil changes). It's not like it's expensive either.

 

[SPED1]

Ever since Crane Cams got put out of business in 2009 EVERY camshaft manufacturer OEM and aftermarket has had issues with hardness and lobe wipeouts. Mikronite, the former owner is still in business. Makes me wonder if there was a proprietary heat treatment that somehow has been forgotten or lost in the search of selling more parts..........

 

[Flyboy2109]

I am a fan of ZDDPplus additive. Restores the zinc compounds that USED TO BE in diesel engine oils. Problem is that it can clog catalytic converters with zinc on loose engines. I use it in my dual diesel boat, my 1958 Cadillac, and my gas powered 383 stroker 1994 Suburban that has headers and cat removed.

Anybody have more info on the cat clogging issue? Maybe ZDDP can be used as long as the engine is tight and doesn't pass oil into the exhaust?

I am suspicious the recommended 0-20 wt oil used in the '23 gas Glad. Seems mighty light, especially where it is warm. Additives may be the answer, where's my STP? But then, I was suspicious of running 5-20 in our LS powered CTS-V also. Somebody says that is because of smaller oil passages and the tighter clearances require lighter oil for a good friction reducing film.

Meanwhile, passed my first oil change at 2400 miles.

 

[bakobobby]

A thinner oil will do better in theory at removing heat. MPG also improves, again in theory. Newer engines have much tighter tolerances than those of decades past enabling running these oils. Modern high end synthetics are much improved over oils of the past. With respect to breakdown under load and oil life. I trust the corporate engineers and bean counters know what they are doing ?

 

[jav_eee]

For my Jeep I just do OCI every 5K miles regardless of what the computer says and sleep very well at night. Where I live in NC we

This is it right here. 5k changes for me regardless. Cheap peace of mind.

 

[ShadowsPapa]

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?

LOL - not sure this one deserves the real world information on this.
This has been hashed here and other places for years.
Textbook example?
WEIGHT or VISCOSITY has nothing to do with "film strength".
Diesel oil is the worst possible oil to run in a gas engine. I can give you some technical reasons if you care but that post tells me you are going by internet crap and don't care about facts.
NO, diesel oils don't have a "more substantial additive pack".
There's just so much wrong with that post it would take a long page to rip it apart.

I am a fan of ZDDPplus additive. Restores the zinc compounds that USED TO BE in diesel engine oils. Problem is that it can clog catalytic converters with zinc on loose engines. I use it in my dual diesel boat, my 1958 Cadillac, and my gas powered 383 stroker 1994 Suburban that has headers and cat removed.

Anybody have more info on the cat clogging issue? Maybe ZDDP can be used as long as the engine is tight and doesn't pass oil into the exhaust?

I am suspicious the recommended 0-20 wt oil used in the '23 gas Glad. Seems mighty light, especially where it is warm. Additives may be the answer, where's my STP? But then, I was suspicious of running 5-20 in our LS powered CTS-V also. Somebody says that is because of smaller oil passages and the tighter clearances require lighter oil for a good friction reducing film.

Meanwhile, passed my first oil change at 2400 miles.

Oh, no, not another "more ZDDP is better" believer. That's so 1970s.
Did you know that too much causes DAMAGE? The film thickness actually stops building and after that, it causes damage to the metals.

I have never ever used any additives in oil, EVER. I've never lost an engine or any parts like cams, etc.
Additives can actually REDUCE the ability of oil to take the pressures and to protect.

Get out and read - but not forums.

 

[JTR178]

I have nothing to add other than it's 'piqued' not 'peaked'.

 

[hjdca]

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.

 

[Shopshirt]

This one peaks my interest. I used to run T4 in my Goldwing, and I used their Gas Truck oil in my JK. Always been a Rotella fan.
https://rotella.shell.com/en_us/pro...-vehicle-5w-30-full-synthetic-heavy-duty.html

I used Rotella T in my touring bikes as well.

I hear this works

I kid...I kid!

 

[TheRealStreetcommander]

Thank you, Flyboy2109 for offering your first hand experience. ZDDP is a great anti-wear additive from what I understand. You didn't recommend everyone shot load their oil with a 90% concentration of it, so I'll assume you trust that clever folks reading the forum can do some research and figure out if and how much ZDDP product is right for them. Good feedback to hear it hasn't hurt any of your engines.

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. No chemistry required on my part. This is why I've used the HDDO for so long. The diesel oil formulations were initially exempt from government mandated wear-additive reductions. Now they may be subject to a variation of them, but at a much reduced stringency, is my understanding. Unfortunately, the HDDO's also tend to be on the heavier side, which is why I was curious to hear pentastar users' results with xW40s and other HDDo's. Looking at the VOA for the Rotella multi 5w30 and some euro-spec 0w40s, they seem like they may be very good formulations.

Our pentastar cam big lobe interface is very similar to the old flat-tappet cam system. Flat tappet cams were being wiped out when the modern oil formulations began distribution. --this was magnified during break-in and it's well documented. I'm not claiming there's parity between the mechanical loading profiles of our big lobe and the legacy flat-tappet cams. They seem more similar than different though. The minority of cam-failure engines may have had different results with better film strength.

ASTM has standardized tests that objectively demonstrate the wear protection characteristics of different oil formulations and viscosities. The data is not a direct analog for engine wear, but it is very useful for making good oil performance projections.

Doesn't sound like any forum contributors have had negative experiences from using the HDDO's or euro-spec 40s. I'll report my results over the coming months/years.

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