Originally Posted by PeterPolyol
Specs are fine for being assured minimum requirements in a handful of parameters,
Handful? Porsche A40 testing is literally various operating tests to simulate regular driving followed by 5 extended (hour-long) runs of a race track (the Nurburgring) followed by a completely tear-down with measurements. That's not a handful of parameters, it's an entire mechanical tear-down and inspection to validate performance under insanely torturous conditions.
Originally Posted by PeterPolyol
it's too bad real-life parameters are infinite and uncontrolled. Plenty of products (in general) pass QA and durability testing only to fail IRL.
Yes, like Pour Point as an indication of cold temperature performance, which is why it was revised to use CCS and MRV.
Originally Posted by PeterPolyol
The Euros, Germans in particular have always demanded certain specs and high viscosity (even if it's fake VII viscosity

), but let's be honest, their engines leave a lot to be desired in terms of oiling systems. Arguably, they get the most synthetic 0Ws around (because specs demand it), yet many of the engines are quite prone to sludge and varnish.
Prone? VW's sludge fiasco had nothing to do with the correct lubricant. It had to do with dealers using sub-par lubricants in engines that spec'd extended drains. BMW's varnished on OEM 5w30 due to insanely long drain intervals, which were eventually shortened. Those kinds of intervals would varnish any engine. I've seen "regularly maintained" engines run on API 5w30 that look far, FAR worse than most BMW mills run on OLM drains.
Originally Posted by PeterPolyol
Some even need 10W60 to stay together... [censored]?
Some high-strung M-cars call for 10w-60. So do Ferrari's. Ford spec's 5w-50 for their high power offerings, GM 15w-50, or do you ignore those examples because they don't fit the narrative?
Originally Posted by PeterPolyol
Compared to a Japanese engine running GrIII and II 20 blends, why don't they suffer such consistent varnishing
Are we forgetting the Toyota Sludgers and the Honda VCM engines? There have been plenty of sludged and varnished Japanese vehicles posted on this very board.
Originally Posted by PeterPolyol
and wiped cams (VW) or bearings (BMW) etc? (can't help but think how much differently, straighter the oils are formulated.....) It's a paradox!!
Hyundai's are currently lunching rod bearings at nowhere remotely close to the power density of a BMW S-series engine. GM had engines eating cams for years and couldn't keep a timing chain in the HF V6. This is impotent Euro-slagging masquerading as technical critique.
Originally Posted by PeterPolyol
Or is it?
Compare the base viscosities used. Compare the reliance on VIIs.
Have you? How much VII do you think it takes to blend an oil with a VI of well over 200 with a Group III base? How much VII do you think is in an inexpensive 5w30 with a Noack of 14%? The Mobil blending guide shows 11.6% VII for a PAO-based 0w-40, and 9% for a Group III/PAO mix. The Yubase blending guide shows 9.1% VII for a Group III 5w30. A Group III 0w-20 with a VI of 173 is 7% VII.
The Mobil blending guide also shows a 5w30 with 11.74% VII leveraging a 6cSt base oil.
Originally Posted by PeterPolyol
If you take the driest base fluids like PAO, which absolutely rejects contaminant solubility/dispersency, choose the lowest viscosity of such and then load it up with plastic (acrylates) and rubber (OCP) VIIs that are less stable than the base oil to meet viscosity, and what will you expect? The oxidation stability of the PAO is mitigated by using a) the lowest viscosity of such (4cSt)
4cSt is not the lowest viscosity. Mobil makes three different 2cSt PAO's. And yes, PAO is dry, which is why you blend it with something else. This is pretty basic stuff.
Originally Posted by PeterPolyol
AND b) the load of VIIs. Not even to mention relatively poor NOACK vs the other grades.
They are all loaded with VII's. Poor Noack versus what other grades? All the 0w-40's are under 10%, there are PLENTY of other oils that are much, MUCH higher than that including most 5w30's tested by the PQIA and pretty much every Japanese spec 20-grade you just praised.
Originally Posted by PeterPolyol
The dispersant gets NO help from the base oil to keep junk in solution, so where is the next likely place for the junk to go than onto the internal surfaces of the engine? But wait, it gets better! Once a layer of polar junk varnish is established on the metal surfaces, those surfaces actively PULL more junk out of the oil which naturally wants to reject it and the varnish layer builds up even faster! No wonder so much varnish winds up on the metal surfaces instead. Then there's the temporary and permanent shearing. VII laden, wide-spread grades also feature oil films that break down more rapidly at high temperatures NOT tested for.
Deposit control is actually a tested for parameter. Perhaps less baseless spin and more research?
Originally Posted by PeterPolyol
If used oil analysis are any indication, the HTHS and fake viscosity doesn't even yeild better ring wear vs a less VII laden oil.
Well, luckily it's already well-established that they aren't, so we can flush that floater.
Originally Posted by PeterPolyol
Why should that surprise anyone? What are the VIIs doing in the ring pack?
They same thing they are doing in your 5w-20 and 5w30's, or your 10w30. This is again why there are test sequences to gauge ring deposits and piston cleanliness.
Originally Posted by PeterPolyol
Breaking down to the base oil viscosity that's what! (what does a 4-5cSt base@a lowly 100C look like at 250+C? What does 3.5cP of VII HTHSV look like at 250+C? No one seems to care about viscosity behaviors past CCS, 40C, 100C and 150C...
Working just fine based on the numerous OEM tests being performed on the oils actually. And most of the guides show a 4cSt and 6cSt blend of bases for a 0w-40. The one XOM guide shows them at 34% and 40% respectively. The same guide shows a 17% and 53% blend of the same bases for a 5w30. These are of course evil PAO. A Group III Yubase 5w30 shows 60% 4cSt and 20% 6cSt + 8.75% VII.
Originally Posted by PeterPolyol
b-b-but that's a stereotype, not every German engine is varnished
And congratulations to all who have clean German engines, but what does it mean? That less VII-reliant oil won't do any better in any other part of the engine?
By time you're seeing varnish under your valve cover, better believe the filth is well established on your rings. Even if engines can run rather acceptably with varnished rings (like MOST engines do), that's not something I want to allow because things can go south fast, like oil burning and compromized ring sealing. I'm not an apologist for oil burning like many on here are.... I find it absolutely unacceptable and will do nothing to further enable it, and everything to mitigate it.
Sorry, I didn't realize you had your own piston cleanliness sequence recognized by the SAE? Can you enlighten us on how this differs from the current protocols employed by everybody else blending the oils being slagged here? Perhaps you should write Porsche, I'm sure their engineers would love to be educated
How many engines have you operated under controlled conditions on these various lubricants and then physically disassembled to validate your theory here?
Originally Posted by PeterPolyol
There is no HTHSV test higher than 150C that I'm aware of, but there are local areas in an engine that handily exceed 150C. No one likes ring deposits, and virtually every engine has them. Why would I want to put enormous plastic (or rubber) tumbleweed molecules in that environment, regardless of base oil? And especially when I'll never take advantage of the 0W rating it was built for..... the WHY begs for justification.... a reason that is more comprehensive than "but printed materials tell me so".
That's fine if that's what you're about but it's about optimization for me, not idiot-proofing. It's not about getting more miles out of the engine, it's about getting more QUALITY miles out of it ie. best compression, cleanest ring packs for as deep into the service life as possible... nuances of machinery maintenance
'Good enough', 'fine' and 'acceptable' aren't goals of mine. If I don't need the cold cranking, I don't need the base 4, the rubber or the plastic in my oil. Simple as that. This is the path my oil journey has taken me to
So you are running an oil you blended yourself then? Because otherwise I can't see how you can know what base oils or their viscosities the lubricant you are using is blended with. Porsche A40 has a ring and piston cleanliness parameter as part of it, I'd wager that so do all the Mercedes sequences and the VW ones. I'm sure they are far more rigorous than whatever you've dreamed up to validate your personal choices here.