Originally Posted By: ChrisD46
"Pick a dexos1 Gen 2 0W-20 with low ash (low detergent) content (most intake-valve deposits are ash, especially coming from the detergent) and PAO or GTL base oil. I would say Mobil 1 Extended Performance 0W-20 is a good choice. PPPP 0W-20, TGMO 0W-20, and Super Tech High Mileage 0W-20 are also good choices, not necessarily in the order written.
* Definitely avoid high-ash (high-SAPS) oils such as ACEA A3/B4, which are detrimental to the intake valves of GDI engines. If you can find ACEA C1 or C4 low-SAPS oils, they would be a good choice, too.
* Go with the thinnest base oil possible (0W-xx), as thicker base oils may have too low NOACK, which increases deposit formation due to decreased volatility (decreased evaporative cleaning), and also have less cleaning ability due to higher aniline points".
*Based on above , would 0W20 Castrol and Valvoline (for example) make poorer choices due to their formulation versus the choices for 0W20 listed above ?
The research papers have told us that the intake-valve deposits (IVD) are caused by liquid oil -- mainly the oil-mist droplets coming through the PCV -- and not the evaporated base-oil vapors. Therefore, I think it's fair to assume that the TEOST 33C deposit test correlates well with the IVD.
Here is the data for
5W-30 oils (
not 0W-20):
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
http://amsoil.com/lit/g3115.pdf
Again, the data is for
5W-30 oils (
not 0W-20).
These are the PQIA test results:
http://www.pqiamerica.com/March2013PCMO/castroledgesyn.htm
http://www.pqiamerica.com/March2013PCMO/valvolinesyn.htm
http://www.pqiamerica.com/March2013PCMO/lucassynth.htm
http://www.pqiamerica.com/March2013PCMO/penzultra.htm
http://www.pqiadata.org/Petro-Canada_5W20.html
http://www.pqiamerica.com/March2013PCMO/mobil1.htm
http://www.pqiamerica.com/March2013PCMO/quakerstatesyn.htm
http://www.pqiamerica.com/March2013PCMO/roylprp.htm
My conclusions:
(1) A lower-ash dexos1 Gen 2 formulation with a hybrid Ca/Mg that reduces the total Ca + Mg content helps.
(2) Exceptional base oils like the Amsoil's and old Pennzoil Ultra's (
without PurePlus) mostly PAO/POE (PAO/ester) base stocks help.
(3) Higher NOACK and thinner base oils help. Three of the top four in the TEOST 33C list had the highest three NOACK's. This is because oils with higher NOACK evaporate faster and spend less time wetting the intake valves, getting less chance to leave deposits behind before they evaporate.
Mobil 1 EP 5W-30 didn't do well at all but it could be a different result for Mobil 1 EP 0W-20, which has more PAO and may also have more POE.
If we assume that current 0W-20's have similar formulations to these 2013 5W-30's, you can then choose from Castrol, Amsoil, or Valvoline, which did excellent in TEOST 33C. Note that Pennzoil Ultra had an entirely different formulation than the Pennzoil Ultra Platinum with PurePlus.
I hope this helps!