0W20 vs. 5W20 Synthetic In GDI Engine ?

Joined
Mar 20, 2016
Messages
3,265
Location
Western S.C.
Originally Posted By: Gokhan
You have a lot of misconceptions. NOACK has nothing to do with deposits. ...
Ha-ha! (Where is Son of Joe when we need him to explain about that relationship?)
 
Joined
Dec 29, 2010
Messages
5,369
Location
Paramount, California
Originally Posted By: CR94
Originally Posted By: Gokhan
You have a lot of misconceptions. NOACK has nothing to do with deposits. ...
Ha-ha! (Where is Son of Joe when we need him to explain about that relationship?)
I hope not because if that's the case, then SonofJoe has a lot misconceptions, too.
Code:
Oil                      TEOST 33C rank  NOACK rank

Castrol Edge with FST    1               8
Amsoil SS                2               3
Valvoline SynPower       3               9
Lucas Synthetic          4               10
Pennzoil Ultra           5               2
Royal Purple HP          6               5
QSUD                     7               6
Petro Canada Supreme     8               7
Mobil 1 EP               9               4
Red LIne HP             10               1
So, there is more of a reverse correlation between the TEOST 33C deposits test and NOACK volatility -- the higher the NOACK volatility, the thinner the base oil is and therefore the more the solvency it has and the more the deposits it can dissolve and remove. And, perhaps, a faster-evaporating oil has less time to leave deposits behind. Of course, the base-oil type plays a crucial type. There is no comparison between Group III and Group II. So, don't compare apples to oranges. Higher NOACK causing less deposits only applies within the same base-oil type. A PAO or a GTL will have less deposits than a Group II no matter what the NOACK is. That's why the PAO-based Amsoil SS did so well in both tests. The additive package also plays a crucial role. The #1-ranked Castrol has a so - so Group III base oil but it did so well probably partially due to its additive package. http://amsoil.com/lit/g3115.pdf The moral of the story: Don't base your oil selection solely on NOACK, with the hope that it will clean better etc.
 
Joined
Aug 1, 2017
Messages
2,345
Location
WA
Originally Posted By: Gokhan
... don't think evaporated oil would condense on hot surfaces. It would simply burn off in the combustion -- the whole idea behind PCV. My intake manifold was clean as new when I examined it, despite the PCV. Also, most oil you get on the intake valves and cylinders comes from transport, not evaporation.
I always thought evaporated oil through pcv causes the deposit on the intake valves that's why some use catch cans ... What is "transport"? Is it oil transport through seals & combustion in cylinder?
 
Joined
Aug 1, 2017
Messages
2,345
Location
WA
i see ... I am guessing you mean oil mist "transported" through pcv and not noack related "evaporated" oil. no?
 
Joined
Dec 29, 2010
Messages
5,369
Location
Paramount, California
Originally Posted By: OilUzer
Originally Posted By: Gokhan
... don't think evaporated oil would condense on hot surfaces. It would simply burn off in the combustion -- the whole idea behind PCV. My intake manifold was clean as new when I examined it, despite the PCV. Also, most oil you get on the intake valves and cylinders comes from transport, not evaporation.
I always thought evaporated oil through pcv causes the deposit on the intake valves that's why some use catch cans ... What is "transport"? Is it oil transport through seals & combustion in cylinder?
Originally Posted By: OilUzer
i see ... I am guessing you mean oil mist "transported" through pcv and not noack related "evaporated" oil. no?
There are four different oil-transport mechanisms. Transport could be liquid oil or both liquid oil and oil mist as in Figure 1(b). See the paper for the detailed explanation. The contribution of different oil-consumption sources (PDF link)* *The contribution of different oil-consumption sources to total oil consumption in a spark-ignition engine Ertan Yilmaz, Tian Tian, Victor W. Wong, and John B. Heywood Sloan Automotive Laboratory, Massachusetts Institute of Technology
 
Joined
Aug 1, 2017
Messages
2,345
Location
WA
Thanks, does the link work for you? I can't absorb any more heavy duty info tonight but I will check it tomorrow .... lol btw, do you think catch cans are useful for GDI engines? The answer may save me $160 grin2
 
Joined
Aug 1, 2017
Messages
2,345
Location
WA
Nevermind, had to copy and paste the link and it works. Clicking on it didn't work.
 

ChrisD46

Thread starter
Joined
Sep 10, 2010
Messages
3,225
Location
GA.
*Seems to me with a greater spread , the 0W30 would have a higher NOACK due to usage of more VII's ?
Originally Posted By: benjy
generally a xxW-30 will have better noack than a xxW-20 of comparable quality + in your area i would use a brand name 10W30 fake synthetic as most $5 a qt "synthetic" oils are today, group III highly refined + processed CRUDE oils!!! i like mobil I extended performance 10-30 said to have some real synthetic in the blend aka PAO. Mobil refines + makes ALL types of base oils!!! but like most will not say whats in any blend.
 

ChrisD46

Thread starter
Joined
Sep 10, 2010
Messages
3,225
Location
GA.
*My understanding was more oil vapors (i.e. higher NOACK) would likely increase deposits ?
Originally Posted By: Gokhan
Originally Posted By: ChrisD46
A number of newer vehicles with GDI engines state to use 0W20 as preferred and in areas where it can not be found up to 5W30 is acceptable (i.e. Mazda Skyactiv 2.0L) until you can locate 0W20 oil . I believe typically the synthetic 0W20 will have a higher NOACK value which in a GDI engine you would want to use the lower Noack 5W20 synthetic oil if you had a choice ? ... *Are OEM's of GDI engines (Mazda again) trying to ensure that with a 0W20 you will have to use full synthetic OR a synthetic blend at a minimum versus stating a 5W20 is also acceptable out of concern you will use a conventional 5W20 instead of a lower NOACK oil in a GDI engine ? Also , if I have a GDI engine (Mazda) , I don't live in a very cold environment - then why wouldn't I want to use a 5W20 synthetic in my GDI engine and enjoy a lower NOACK that would aid in keeping intake valves cleaner than 0W20 with the higher NOACK ? Other than cold start protection I can't see a reason to use a 0W20 synthetic versus a 5W20 synthetic oil ... Your thoughts and experiences ?
You have a lot of misconceptions. NOACK has nothing to do with deposits. Reducing the NOACK is primarily for reducing the oil consumption. Why do you think if an oil evaporates faster, it would leave more deposits? In fact, it's the other way around. Base oils with lower NOACK/lower viscosity have lower aniline points, which means higher solvency and cleaning power. Also, 0W-20 tends to have better base stocks than 5W-20, which also decreases deposit formation. Therefore, 0W-20 cleans better than 5W-20 and leaves less deposits. However, the relative wear performance of 0W-20 vs. 5w-20 is more debatable. It's also one reason why German Castrol and Mobil 1 European Formula are 0W-30 and 0W-40, respectively, instead of 5W-xx -- European engines require better cleaning. See the section under solubility. Lower aniline point indicates higher solvency: https://www.tri-iso.com/documents/exxonmobil_chemical_spectrasyn_plus_Brochure.pdf
 

ChrisD46

Thread starter
Joined
Sep 10, 2010
Messages
3,225
Location
GA.
OK , for the comparison of GTL base stocks : Which is the better oil for a GDI engine using the same OCI : PPPP 0W20 vs. PPPP 5W20 ?
 
Joined
Dec 29, 2010
Messages
5,369
Location
Paramount, California
Originally Posted By: ChrisD46
OK , for the comparison of GTL base stocks : Which is the better oil for a GDI engine using the same OCI : PPPP 0W20 vs. PPPP 5W20 ?
Both would work. PPPP or QUSD 0W-20 would probably leave slightly less deposits than the 5W-20 with the thicker base oil. If oil consumption is an issue, then 5W-20 is better due to lower NOACK. M1 EP 0W-20 (mostly PAO and probably with some ester) could be the oil to go with if you really care about engine cleaning. NOACK should be decent, too, because it's mostly PAO. Any dexos1 Gen 2 oil is good. I would go with 0W-20 instead of 5W-20 unless there is an oil-consumption or valvetrain-wear issue.
 
Joined
Mar 20, 2016
Messages
3,265
Location
Western S.C.
Originally Posted By: Gokhan
... So, there is more of a reverse correlation between the TEOST 33C deposits test and NOACK volatility -- the higher the NOACK volatility, the thinner the base oil is and therefore the more the solvency it has and the more the deposits it can dissolve and remove. ...
That's fine, if your only worry is deposits from brand new oil (which 33C tests, unlike Honda HTO-06) on hot turbocharger bearings. How about correlation with the TEOST MHT test, which is far more relevant to me and a lot of other people (including those with Corollas a little newer than yours)? And how about deposits from PCV-borne oil mist on GDI intake valves and in combustion chambers?
 
Joined
Dec 29, 2010
Messages
5,369
Location
Paramount, California
Originally Posted By: CR94
Originally Posted By: Gokhan
... So, there is more of a reverse correlation between the TEOST 33C deposits test and NOACK volatility -- the higher the NOACK volatility, the thinner the base oil is and therefore the more the solvency it has and the more the deposits it can dissolve and remove. ...
That's fine, if your only worry is deposits from brand new oil (which 33C tests, unlike Honda HTO-06) on hot turbocharger bearings. How about correlation with the TEOST MHT test, which is far more relevant to me and a lot of other people (including those with Corollas a little newer than yours)? And how about deposits from PCV-borne oil mist on GDI intake valves and in combustion chambers?
TEOST MHT has been removed in ILSAC GF-6. I've already discussed the PCV.
 

JAG

Joined
Oct 23, 2005
Messages
5,319
Location
Fredericksburg, VA
Interesting data has been posted, but in my opinion, it doesn’t apply to PCV-borne intake valve deposits. The aniline point differences between different viscosity grades of same base oil is not enough to be significant. I also disagree with many of the conclusions that were drawn. There are too specifically address each one. I’m not saying I am right. I’m saying I disagree. Check out the graph in the last post in this related thread: https://www.bobistheoilguy.com/forums/ub...u_l#Post4808066 That graph is below which is from here: https://www.tytlabs.com/english/review/rev343epdf/e343_074nakai.pdf
 
Top