whatscooking

I play with about anything with motor, Jeeps, motorcycles, tractors. Coming from the old motorcycle side of things everyone there likes Shell Rotella. High in ZDDP as it is for Diesel motors, no cat. That is where I have read the ZDDP is a cat. killer especially when a motor starts using oil. Seems odd that a lot of you guys are adding ZDDP and using Rotella here. Just asking as it seems that the O2 sensors need to be working correctly with the Jeeps computer.
If you really want to get into some great reading go to bobistheoilguy.com

mschi772

Oil burning, at the level of cat-killing, just isn't that common with our engines. It's honestly that simple as I see it. ZDDP doesn't kill a cat if it can't touch it (never gets burned).

Jeepin'_Aint_EZ

I'll take the risk of killing a converter for the added benefits of the extra ZDDP.

EZEARL

Amsoil's thoughts on ZDDP:

Flat-Tappet Cams
The design of flat-tappet cams makes them especially vulnerable to wear. As the name indicates, the tappet – or lifter – is flat. During operation the surface of the cam lobe slides rapidly over the surface of the tappet, producing high friction and temperatures. The camshaft and lifters are responsible for triggering the precisely tuned movements of the valvetrain

Without the protective film barrier provided by ZDDP, the cams and lifters wear from the force of operation, negatively affecting cam and valve operation. Because most V-8 engines of the muscle car era came standard with flat-tappet cams, the problem is especially prevalent to classic-car and hot-rod owners.

In these applications, modern oils, such as AMSOIL synthetic motor oils, are capable of providing adequate wear protection after the engine has been broken in. But due to variables like severity of service and level of modification, AMSOIL primarily recommends high-ZDDP oils in these applications, such as Z-ROD® Synthetic Motor Oil (ZRF, ZRT) or DOMINATOR® Synthetic Racing Oil (RD20, RD30, RD50, RD60). When breaking in a rebuilt or high-performance engine, AMSOIL recommends AMSOIL Break-In Oil (BRK), which contains high levels of ZDDP for added wear protection.

https://www.amsoil.com/newsstand/cla...ar-protection/

mschi772

If ZDDP was SOOOOO necessary for the Jeep 4.0, then how come so many that have never used oils high in ZDDP still last just as long as those that do and with very similar if not identical wear?

• Are oils like Rotella good in the 4.0? Yes.
• Are other oils like conventional Pennzoil (for example) good in the 4.0? Yes.
• Are oils like Rotella necessary for the 4.0? No.
• Are oils like Rotella significantly better than oils like conventional Pennzoil for the 4.0? I have never seen definitive evidence of this, and I'm a huge oil geek among many other things.

The NEED for high levels of ZDDP in a properly broken-in engine (that is: AFTER the engine has already been broken-in) is a myth. It is a myth that people cling to as if it has woven itself into the very fabric of their identity and to even entertain the possibility that something they believe may no longer be true could lead to catastrophe.

I believe the popularity of such things as fanatical use of T6 in the 4.0 are due to people's commitment to flawed or incomplete information (myths, out-dated info, misinfo, lies, etc) COMBINED with a strong desire to be in possession of knowledge or methods that mimic nuanced expertise.

Yep, it would be nice to believe that we could have discovered a special sauce for our engine that rises well above the rest that sets us and our engines apart from the plebeians who don't know any better especially since we could then benevolently share our secrets with others and feel the pride of knowing we just improved the lives of another XJ and its owner and, subsequently, the lives of everyone they help as well.


Am I judging anyone who uses T6 or similar oils in their 4.0? No. It's not even exclusively a diesel oil (it is rated for use in gasoline engines as well), so it's not like it was ever that out-of-the-box thinking for the first guy to ever try it. It's a great oil for a good price. I've used it. I could very likely use it again.

Am I judging anyone who says it should not be used because "it's a diesel oil," "synthetic oils cause leaks," or "ZDDP kills cats?" Yes, I am judging those people.

Am I judging T6 (and similar) users who feel they are superior to others based on the oil they use? Yes, I am judging those people.


About me:
I am an oil geek that has dived remarkably deep into the oil, oil science, UOA, etc rabbit hole and come back up. Please, unless you work in the actual oil industry or are active in something like automotive racing which has demands on engines far greater than daily driving and recreational 4x4's, don't stress yourself out about oil so much. It's not worth it. If you genuinely enjoy the dive like I did, go for it and enjoy it, but keep it in perspective, please--you'll be splitting hairs that most people don't know even exist and will never need to.

From memory, I have used:

• Rotella T6 5w40
• German Castrol 0w30
• Belgian Catrol 0w30
• PYB 5w30
• PYB 10w30
• Pennz high mileage w30
• Mobil 1 0w40
• Quaker 5w30
• Quaker 10w30
• Valvoline 5 or 10w30 (can't recall which it was right now, but it was so long ago as to not matter anymore)

My XJ is currently running PYB 5w30 and running strong and clean at 205k miles. It has been my XJ since it had approx 130k miles. I plan to give Pennz Plat and/or Pennz Plat high mileage a go in 2018, but it will honestly probably just be wasted money as there isn't really much if any room for improvement beyond what PYB is doing already.

Bugout4x4

Me too... and since we don't have smog in our region, it's going to get punched out when it does. Lol

jpz

You can make that 3 now. Regular old oil is all that goes in my XJ. There has never been anything but whatever is cheapest in her. Shockingly she still purrs along.

extrashaky

Are you old enough to remember the Pepsi Challenge? I am. Pepsi did taste tests all over the country with real people, where they had two unlabeled cups of cola they allowed people to taste (not drink), then choose the one they liked better. The majority selected Pepsi.

Yet the majority of buyers kept buying Coke. More people preferred the taste of Coke in real life. If they preferred Coke in real life, why did they say they liked Pepsi in the Pepsi Challenge?

Because the test was rigged. It was designed to take advantage of a peculiar sensory and psychological phenomenon in which if a person is offered a taste of two substances, he'll prefer the sweeter of the two. However, after the first taste, the taste perception changes and the sensory response is altered so that the sweeter option becomes less attractive and in some cases repulsive. If you allow people the opportunity to drink the two choices, the majority will choose Coke.

In the real world people weren't just tasting these beverages. They were drinking them. So the Pepsi Challenge was not representative of the real world and not predictive of real world outcomes.

If the makers of these oils and additives really want to test their products, they'll do it in a real engine in real world conditions. It'll involve the exact same motions, the exact same temperatures, the exact same changes in temperature and all the other factors only a real engine can provide. Any testing apparatus that doesn't mimic the real world exactly is automatically suspect, and I wouldn't trust it because it could easily be designed to provide exactly the outcome they want that doesn't necessarily mirror the real world.

The implied conclusion is that you should buy their product because it provides more zinc than regular passenger car motor oil. But nobody has provided any scientific evidence to support that. Marketing gimmicks dressed up as educational seminars are not scientific evidence.

5-Speed

Your coke vs pepsi example doesnt work as a good example to me. People can make choices, metal cant. Its going to do the same thing everytime.

As for oil companies showing you real examples like running a Jeep engine 400k miles combined with real world conditions, well they cant do that in 15 min so it wouldnt work for their classes (and no the class wasnt 15 min, each test was). Instead they simulate whats going on inside an engine in a fraction of the time. Again, we are talking about metal on metal contact, its going to do the same thing everytime unless something is added to the equation. And if they can show that in test 1 with no additives that the metal gets scored but in test 2 with additives it doesnt, even if the test is rigged to be on their side, they still showed that the additive at least did something. Yes its not exactly the real world sample you are looking for but it creates some of the same effects in a lot less time. Trust me, I get what you mean about real world simulations. No oil company is going to spend the money to do that. As you pointed out, they make their money on selling people hopes and dreams based on the magical ingredients they put in the oil. Arguably, some work, some dont. Some of it is scientific, some a money making myth. Therefore, what you are asking to be proven never will be proven and we will never have the facts you are trying to show.

Edit - response to your last sentence, can you argue that zppd is scientifically designed to bond with metal to create a barrier for metal on metal contact? If so, how is that bad?

So where does that leave us? About the same place as you saying that Rotella leads to cat failures from high zinc content. If that was true, why dont we see all these post about it since everyone is running Rotella or a high zinc oil? I have seen more wiped lobe threads over clogged cat threads by far.

mschi772

I said it in my first post, but I want to repeat it so that any interactions with me don't result in antagonistic fights.

I'm not ANTI-T6 (or similar). It's a fine oil. What I'm against is the ignorance that leads people to believe that if you're not running it or some other high-ZDDP oil, you're running an inferior oil.

I don't even know if there is such a thing anymore as a bad oil for the 4.0. Once upon a time, I might suggest that conventional Mobil 1 products were a bad choice given the consistent UOA results I saw, but by now for all they've changed. Or maybe they haven't. There certainly are oils that are better than others. Do your own research and all will be well. But do research, don't just latch onto something that sounds good and zealously assimilate it into your belief system.

People, especially in this community, have very different attitudes regarding cams vs cats. Likely there are a lot more cat problems of all kinds occurring, but are less likely to be discussed because of how easy it is to just replace a cat without needing or wanting to understand what the failure exactly was. Combine that with how often people ignorantly punch or delete their cats, and the likelihood of seeing cat failure discussion falls even further. But if your cam fails or is found during service/rebuild to be excessively worn, I'd say one is more likely to want an answer and to discuss it in public.

And, again, since ZDDP-related cat failure is dependent upon oil being burned...I just don't see many 4.0's burning oil. They love to leak it externally of course, but they seem pretty good about not burning it.

Outlaw Star

Now then. The staff has been kind enough to issue their warnings, so either stop trolling and targeting or move along. I hear ClubXJ on fb needs more trolls anyways.

Rogue4x4

Again...AMEN

RocketMouse

I agree with this with some respect. Ignorance is ignorance regardless. Now if I choose to run T6 in mine because of having a little higher zinc content than another oil....and I've read reports where for this type of engine may have benefits, and it doesn't cost me any more to use it and it's a quality oil... then so be it. But me using T6 in my has nothing to do with thinking that other oils are inferior. I don't personally think that. These days a lot of them are pretty close. This is really nitpicking at its finest here. lol.

Bugout4x4

Really? Unless you are using the term "grammatical" as code for something else that's a little ****. It's a car forum not a writers or english teacher's forum. And most are posting from their phones which causes additional problems. Definitely in the wrong forum if you don't want to rub shoulders with bad grammar. As it is with many auto forums. This one is actually not bad compared to some of the gun forums I have been in. Want to see some real bad grammar go to a couple sports forums. lol

PatHenry

Unless we can all agree that the Oxford comma use must be strictly enforced, I can no longer be a part of this forum!

I also demand that anyone who uses "their", "they're" and "there" incorrectly be immediately banned.

Oh no, oh dear goodness no!!!!!!