Which are true(!) PAO (Class IV) Motor Oil brands?

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Hi,
I want to use Full Synthetic Motor Oil, and I have been searching high and low (both in this forum and on the web) for a list of TRUE Class IV (PAO) Motor Oils... - but to no avail. There's just no definite list out there; just opinions and hearsay.

I am aware, by now, that this is a highly debated question, and that motor oil manufacturers are simply not telling the (entire) truth about their products. Example: "Full Synthetic" may not necessarily mean it is entirely(!) synthetic; best examples being "Castrol Syntec" and "Mobile 1" - which are PAO-base, but have a much higher percentage of Class III base stocks mixed in. To me, that's simply a lie (or cheating). Even though these may be "good oils", they are just a "blend", and not truly synthetic... and I don't care about those.

From what I could find out thus far, only "AMSOIL" seems to produce true PAO/Class IV-based Synthetic Motor Oil.

Now... here's my two-fold question for you:
1.) What other Class IV/PAO true Synthetic motor oils are 'out there', that I could buy in the car shop around the corner (..instead of having to order by mail as it is with the Amsoil juice)??

2.) Apparently, labels on oil bottles that claim to be "[Fully] Synthetic" give no indication of their true base. -- So, HOW CAN ONE BE SURE it is a Class IV oil, and not a blend??

P.S.: This is not about which oil works best for you; I'm sure everyone has favorites and/or opinions. This is just about the FACTS.. and which brands are truly PAO/Class IV-base motor oils.

Thanks, Guys... - much appreciated!!
 
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Group IV oils that are all group IV have poor seal compatibility and additive solubility so they do not exist. Between additive carriers and esters, alkylated napthalenes or other stuff added to help the oil be more soluble and seal compatible, I doubt any oil is more than 90% PAO.

Castrol Syntec 0W-30 that says it is made in Germany is primarily PAO.

Basically all grades of Mobil 1 are primarily PAO. I doubt any grades are less than 70% PAO. The 0W-20, 0W-30, 0W-40, 5W-50 and 15W-50 are all vastly group IV/V base, there is debate about the 5W-30 and 10W-30 but nobody really knows for sure.

Valvoline SynPower is primarily group III with PAO blended in.

Pennzoil Platinum, Quaker State Q, and Castrol Syntec that is not the 0W-30 made in Germany plus most other off the shelf "synthetics" are group III. I don't know the origin of the Platinum and Quaker State bases as far as production technique but if they use Shell's XHVI base oil, which is a group III made from slack wax produced in hydrocracking base oil, it is fundamentally (and somewhat oxymoronically) a fully synthetic group III.

The lines are very, very blurry.
 
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Thanks, MGegoir, that's a start! Didn't know about the poor seal compability... thanks for the info.

Also, I've heard of the German-made "Castrol Syntec" that's supposed to be primarily PAO... Any idea where I can buy that?

Thanks for your insightful response!!!
 
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AutoZone is the easiest place to get German Castrol. Only comes in quart bottles. Judging by your username, you are running a BMW, and it is an A3 rated oil that is on the thicker side of a 30 weight, almost a 40 weight, and carries many BMW approvals. It is comparable to Mobil 1 0W-40 which is their flagship oil and is used in machinery as expensive as Honda IndyCar engines and Porsche factory race cars.
 
What really amazes me is the companies want you to spend 6 dollars on up for their oil yet if you call them and ask what is in it they will say proprietary. Yeah right. like it is a secret if you want to spend the $$$ a lab can get you a pretty good idea what is in the oil .
 
Some Autozones have the German castrol, M1 0w/40 supposed to be syn,supposedly Valvoline euro oils are real syn.
 
Originally Posted By: BeamerDude
MGregoir

So, only the German-made Castrol Syntec 0W30 is the real deal? But, isn't that more a cold-temperature oil? ("0W")?


Yes, there is American made Syntec that is Group III (the base oil is made by Petro-Canada) based, but the German made is PAO. In Europe, it is sold as Castrol Edge. The cold temperature thing is not an issue, it does not comprimise the high temperature performance of the oil for the benefit of low. In fact, it is better because the oil will flow faster at low oil temperatures, protecting better.

Mobil 1 0W-40 and Castrol Syntec European Formula 0W-30 are quite comprable oils in every way, and both are the PAO based oils you are looking for.

I believe Steve is referring to the non-ILSAC (ILSAC covering 0W-20, 5W-20, 5W-30 and 10W-30) grades of SynPower. There is a 5W-30 MST, 5W-40, 5W-40 HST and 20W-50 that I have heard are primarily PAO but never had verification one way or another.
 
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Vavloline currently has a 5W-40 that has the Euro specs listed. It is a relatively thin 40 weight at operating temps like most Euro 5W-40's. (That is, compared to a CJ4 or CI4 5W-40 diesel rated oil) The German Castrol 0W-30 is actaully a bit on the heavy end of the 30 range at operating temps, so they are really close actually. The 0W part has more to do with how well it flows at extremely cold temps such as -20 to -40F.
 
I bought some "domestic" Castrol Syntech (5W30) in the store today.. - before I did some research on the web. Bad idea...

Well, the Castrol sure won't hurt my engine, I'm sure - but I wanted to get some "real" syn, and not just a mix. Now it has -sort of- become a personal thing; I refuse to buy motor oil that doesn't clearly say what it's based on (at least, I'd like to).

Seems like I will have a hard time ever being sure. I'll probably return the "mixed" Syntec and try to get some of the (as-close-as-it-gets to the)"real deal" (PAO) Castrol then. Or, I'll try the M1... The latter one seems to have quite a 'fan base' out there.. :)
 
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Yeah right. like it is a secret if you want to spend the $$$ a lab can get you a pretty good idea what is in the oil .


It is a company's IP, not subject to publication. Is that unreasonable?
 
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Perhaps after you gather all of the inputs, you can tabulate them and then post it up as a clean list. We can then make it a sticky so that this topic does not come up time and time again.

Thanks,

JMH
 
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There is much historic data available in the search engine. You will never get an accurate compendium of motor oil base stocks. Before you finish one of the formulas will likely change. Instead of relying on the synthetic moniker why not look at the ratings. Need a long drain euro oil? The euro A3 spec is what you are looking for. Want a lower visc high performance oil? A5 is it. Then there is the new Honda spec and manufacturer specs from BMW Mercedes Porsche etc that are indicators of an oil meeting performance criteria set forth by the designers. Don't even have a vehicle that has these specs? Just SM GF4Energy conserving oil? Buy whatever SM Gf4 Energy Conserving oil that makes you smile.
 
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Originally Posted By: MGregoir


Basically all grades of Mobil 1 are primarily PAO. I doubt any grades are less than 70% PAO. The 0W-20, 0W-30, 0W-40, 5W-50 and 15W-50 are all vastly group IV/V base, there is debate about the 5W-30 and 10W-30 but nobody really knows for sure.


What`s the current word on M1 10W40 High Mileage? I search and read on a lot of car chat forums and this oil doesn`t get a lot of exposure. I`m considering giving it a try. I want to go to a 40 wt oil on my next oci and I`ve been satisfied with M1 products,plus it`s a competitively priced synth.
 
Someone putting-in even a modest amount of searching will find that PAO content is pointless. There are 100% hydroprocessed "synth" oils that work as good as or better then oils advertised or implied to be "pure" or "real" synth. Various base fluids have plusses and minuses and it's well-known here that a MIX of several bases produces the best product. Castrol know this and used this formulation for a long time now and took unwarranted abuse for doing so. Now we have noisy/high Fe wear Mobil 1 that has a shady and unknown bese oil anyway.

What are you trying to gain from "real" synth oil content research? Are you going to make a big matrix and plot all the pecent of PAO vs the cost and "find" the "best" oil that way? What about pennzoil Platimum? Appears to be one of the best otc oils ever sold...all HC/G-III base oil. It's dirt cheap and works excellent...what about that?

If you put as much effort into developing your own knowledge base as absuing the forum itself, you would be doing everyone a favour.

So, go ahead and explain what your point is, just a general survey of PAO percentages for trivia purposes or a meaningful engineering endevour?
 
Oh, here's another great example of why you MUST have a ALL PAO oil. Awefull Castrol Syntec G-III base oil changed every 10k miles after 122k.
122k_miles.jpg

Look at how badly these types of oil perform! How could someone sleep at night without PURE PAO oil? How could my 10 year old Honda look just as clean on dog-dirt dino oil? Quick, PM Dr.Haas and warn him about dino oil in his new Ferraris and Lambos. Just explain to him how pure PAO is the only oil aceptable for use.


Oh, another G-III engine. Snap, it's a turbo to boot.

1.8tVC.jpg
 
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