Pennzoil Synthetic Blend... NOACK #s??

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wemay

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I know the 'full syns', QSUD/PP/PU all have low NOACK #s but I cannot find any information for the PSB 5w30 formula. Anyone?
 
wemay,

The SOPUS published value is 13.0% for Pennzoil Syn-Blend 5W-30, which is the upper limit to meet the DEXOS certification.

However, there is more than just NOACK to consider when looking for an oil that does a better job regarding the deposits DI engines leave on intake valves (actually all engines do this to some degree, it's just that port injected engines spray fuel with its cleaning additives to keep the intake valve face clear, preventing the deposits from accumulating.)

The TEOST ratings of the oil, which is an ultra high temperature oxidation test may give a clearer indication of deposit resistance of an oil. And NOACK ratings and TEOST do not necessarily track hand in hand.

Case in point, Castrol Edge FST had the best independently tested TEOST numbers, but according to PQIA, had a 11.0% NOACK, compared to Mobil 1, which had a mediocre (higher) TEOST number, but tested with a lower (10.1%) NOACK.

And Pennzoil has said that valve deposits are more a function of the type of additives used, mostly likely of the organic variety, as opposed to base oil characteristics, which NOACK and TEOST are affected by.

So, good luck with testing whether your oil selection has much of an impact on DI valve deposit accumulations.

As others have stated, PCV/oil-separator design and effectiveness along with other design factors such as high intake valve stem temperature probably impact whether oil vapor in suspension/solution "precipitates" out on the valve face, or instead, is carried into the combustion chamber and burned.

Take care,
Gary
 
And interestingly, regarding injection nozzle location, some manufacturers, such as Ford, try to compromise.

In their 3.7L V-6 engine, they advertise that the fuel nozzle location is a hybrid between port and direct injected designs, in that it is positioned, so that when the intake valve is starting to open, fuel sprays across the face cleaning it, but as it further opens, the fuel path enters the chamber unimpeded by the valve. This supposedly gives most of the benefits of DI, specifically, more combustion chamber cooling (allowing higher compression for a given fuel octane rating), and better emissions control.

But DI engines, particularly turbocharged ones that use extra fuel to cool the chambers to limit preignition and detonation, probably can benefit from using a lower ash oil, which all common SN rated Mobil-1 oils have, either at 0.8 or 0.85%, as opposed to many competitor's oils which 0.9-1.0% sulfated ash. This again shows how the total package impacts an oil's effectiveness as opposed to focusing on one factor such as NOACK or TEOST.

And there are those who advocate driving a DI engine hard, in order to control some of the deposits. This undoubtedly will help with the deposits inside the chamber, particularly on the top of the piston, but may not do much to help with the intake valve face deposits, unless high load driving increase the intake valve temperatures.

So, again who knows, what is effective, both in oil selection and driving style to combat the deposits and keep the engine efficiency (mileage and power) up.

Gary
 
After having my questions discussed on other threads about the GDI-T 2.0 and thoroughly reading thru this one, i will be using any of these @ 3500 OCI and call it a day:

M1 5w30
QSUD 5w30
PP 5w30
Val Synpwr 5w30
Castrol Edge or Titaium 5w30
Maybe even
Pennzoil Syn Blend 5w30 (50% syn)

87 octane, Shell/Mobil/Chevron/BP

ThE iNsaNity oF it ALL!
 
Actually..I think my next oc will be PYB 5w30. It actually surpasses Hyundai specs and i'm beginning to think that no better spec is needed between Hyundai's recommended 3-5k mile oci for the vehicle. They recommend good old QS dino. Good enough for specs, good enough for me. I really think ive been over analyzing.
 
Changed mine today and actually went with my old favorite:

Valvoline 5w30 conventional
Valvoline VO106 oil filter
3k mile oci
 
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