Is PAO (Group IV) no longer important?

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camrydriver111

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I remember 10 years ago there was a lot of discussion about which oil has the most PAO. People's goal was to use the oil with the most PAO because performance was better than Group III.

Now people are telling me that the only difference between a semi-synth and a full synthetic is $3 to $4 per quart.

I have been away from the oil scene for a few years. Why has Group IV fallen out of favour? Is there new research to suggest it doesn't protect as well as Group III?
 
Not at all, Gp4 is still king if we look at base oils in isolation. But the benefits are only realised if you do long drain intervals, which nobody seems to advocate anymore with TGDI engines being prevalent.

gpIII+ oils like Gas-to-Liquid have also narrowed the performance gap.
 
camrydriver111 said:
I remember 10 years ago there was a lot of discussion about which oil has the most PAO. People's goal was to use the oil with the most PAO because performance was better than Group III.

Now people are telling me that the only difference between a semi-synth and a full synthetic is $3 to $4 per quart.

I have been away from the oil scene for a few years. Why has Group IV fallen out of favour? Is there new research to suggest it doesn't protect as well as Group III?
Click to expand...

IMO it was really about price. People were paying PAO prices for Group 3 product and the feeling what that the Gr 3 product didn't perform as well when compared to PAO. Group 3 oils came out round 2007. Beginning around 10 yrs ago GTL came on the scene (Gr3+) which basically carries the same performance advantages/disadvantages as PAO.

PAO hasn't fallen out of favor per se but the addpack has become more important with ever lower viscosities used today.

Edit: https://www.stle.org/files/TLTArchives/2022/09_September/Cover_Story.aspx
 
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camrydriver111 said:
I remember 10 years ago there was a lot of discussion about which oil has the most PAO. People's goal was to use the oil with the most PAO because performance was better than Group III.

Now people are telling me that the only difference between a semi-synth and a full synthetic is $3 to $4 per quart.

I have been away from the oil scene for a few years. Why has Group IV fallen out of favour? Is there new research to suggest it doesn't protect as well as Group III?
Click to expand...

PAO has always had its share of advantages and disadvantages. It is important to note that not all PAOs are the same. The choice of olefins as raw materials plays a significant role, as dodecene possesses distinct characteristics compared to decene. Furthermore, the production methods and catalysts used can vary, further influencing the final properties of PAO.
PAO itself is a mixture of oligomers. The increased viscosity of PAO (from PAO 3.5/4 to e.g. PAO10) adds complexity, resulting in a higher presence of C10 (C12) branches, giving it a polymer-like nature and introducing certain challenges. Even PAO8 is essentially a blend of tetramers and pentamers.

paos.webp


As a component in compositions, PAO, such as PAO 3.5, serves as an excellent base. To address any PAO challenges, additional "rings", such as ANs, are often added since PAO itself lacks inherent rings (naphthenes). These rings contribute to various desirable Group III properties (e.g. - The all-hydroprocessing routes taken at S-Oil’s aramcoULTRA base oil plant ensure almost complete removal of aromatics and impurities in the final product while leaving most desired components like isoparaffins and 1-ring naphthenes.)

wax.webp
 
The claim has been made that AN's are better lubricants, and require lower levels of additives.

I have to wonder, as PAO's real claim to fame is the ability to perform properly from -60F to +500F. AN's are not for severe cold, as they don't flow at all under about -30F. And they are not as resistant to coking on turbocharger hot sides as PAO.

As always, many of us are not operating in Antarctic temperature extremes, and don't run 75 pounds of boost in our daily drivers.
 
LOTS of MARKETING for sure, BUT for most of us a typical group III fake synthetic oil is a good value IMO + forget most semi syns as there is NO rules on the amount of synthetic usually cheeper group III that i am aware of. there are better oils like HPL + Redline among others IF you want or really need more performance in extreme heat or cold BUT you PAY $$$ for them!!
 
camrydriver111 said:
I remember 10 years ago there was a lot of discussion about which oil has the most PAO. People's goal was to use the oil with the most PAO because performance was better than Group III.

Now people are telling me that the only difference between a semi-synth and a full synthetic is $3 to $4 per quart.

I have been away from the oil scene for a few years. Why has Group IV fallen out of favour? Is there new research to suggest it doesn't protect as well as Group III?
Click to expand...
Group IV oils are excellent if you have a car that burns oil. The oil consumption rate for conventional and "American Synthetics" are equal while going with a PAO oil halves the oil consumption. A friend of mine had a truck that would consume 1qt of oil every 500 miles regardless of the oil he used so when I switched him to a PAO oil, it cut the oil consumption in half to 1qt every 1000 miles. The Castrol European Formula 0W-40 and 5W-50, and Mobil 1 European Formula 0W-40 all have a high percentage of PAO in their oil and be purchased cheaply at Walmart. Though when I reflect on things, I'm thinking the only criteria that really matters for a car that burns oil is finding an oil with the highest flash point. The oils I mention have a flash point of at least 234C.
 
It was all a wife’s tale and faux value proposition issue.

Is PAO a great basestock with high oxidation resistance and great cold flow characteristics? Sure. Is it the only solution? No. Does it really help in normal use conditions? Not necessarily.

Much of the concerns a decade or more ago stemmed from misinformation from the Mobil/Castrol issues on synthetic oil labeling.
 
I'd say it's not that important in the majority of situations and applications. One of many base oil options. I think group V (solvency) and additive package is more important with today's modern engine demands.

Mobil took an internet reputation hit when the moved to using III in the early 2000s.
 
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if i am reading this correctly, a small blend of say 10% group 4 and group 3+ would make a ideal engine oil ,,like Havoline pro-ds and Pennzoil platinum etc?
 
facility1 said:
if i am reading this correctly, a small blend of say 10% group 4 and group 3+ would make a ideal engine oil ,,like Havoline pro-ds and Pennzoil platinum etc?
Click to expand...
You're making assumptions about blending based upon a hunch? Tribology is more like baking than mixing paint colors.
 
not a assumption,only a observation of what is said,i know blending a lubricant is very complicated.perhaps is why there are so many formulations that achieve similar goals
 
Group IV PAO holds no real world advantage over group III for most applications. Group III+ base oils can outperform PAO base oils in some key areas like additive response and solubility while also being cheaper to make and blend. The only applicable advantage PAO has is in extreme cold weather as it can withstand colder temperatures better than any other base oil group. It used to be that PAO was the king of high temperature performance as well, but even that hasn't been the case lately with the rise of better group III/III+ base oils showing higher HTHS and similarly low volatility to PAO. As a result, PAO has largely been isolated to just oils that need extreme cold weather protection and still isn't the primary base oil in most of those blends.
 
RDY4WAR said:
Group IV PAO holds no real world advantage over group III for most applications. Group III+ base oils can outperform PAO base oils in some key areas like additive response and solubility while also being cheaper to make and blend. The only applicable advantage PAO has is in extreme cold weather as it can withstand colder temperatures better than any other base oil group.
Click to expand...

Au contraire. Solubility is actually a non issue with PAO since no
blender never uses 100 % PAO and it's common to blend it with
ester and/or AN. Every blender will tune the 'sweet spot', say the
final product's aniline point which means an appropriate solubility.

In reality PAO means a PAO/AN/ester blend. The most relevant if
not the only disadvantage: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$ !!!


ps:
Some blendes may add some group I/II on their less pricy products.
.
 
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