Sodium or not?

[ProfPS]

I have noticed that sodium is added to the add-packs in some top shelf PCMO dino brands where it is not used in the same parent company's lower brands. For example, sodium is used in Havoline DS and Mobil 5000, but not in Chevron Supreme and Exxon Superflo. There are UAO's from the non-sodium versions that are very good and some BITOG'ers have commented that they have seen great results when tearing down an engine when the non-sodium versions were used.

For the common BITOG'er who maintains a consistent OCI practice (dino 4-5k OCI), does sodium make that much of a difference in "cleaning"? Does the added cleaning ability have an effect on wear? What about the risk of increased corrosion, and storing an engine for the winter - should a sodium enriched PCMO be avoided as a storing fill?

 

[ARCOgraphite]

Sodium is a metal, like Antimony or Molybdnenum or Zinc used in complex organometallic compounds. They have to (pass SM/GF4 for corrosion and deposit control - dont know if min spec are adequate for all motors. AFA the sodium being MORE reactive at end of life or when "changed/depleted" in the motor - the tribologist/chemist will have to answer.

 

[Ben99GT]

Originally Posted By: ProfPS
For example, sodium is used in Havoline DS and Mobil 5000, but not in Chevron Supreme and Exxon Superflo.


Not sure where you are getting this info from, but from the used oil analysis I've seen neither Havoline or Chevron Supreme contain any sodium.

 

[cven]

http://www.springerlink.com/content/w5n8x33x26341u48/

Does the magnesium sulfonate they speak of in the link show up in a VOA as mag/sodium, mag/sulfer or just mag?

Seems to have some advantages over calcium from the info in the link.

 

[Vilan]

It would show as magnesium and sulphur. The sodium sulfonate is just a preliminary ingredient, the sodium gets replaced by magnesium.