Mobil 1 5W-30 EP, SN Rated with TBN and TAN

[buster]

Quote:
Recent research on low HT/HS oils showed oils using salicylate detergents showed higher TBN retention even with lower starting base numbers .

Also the test oil with salicylate's and low low phosphorous outperformed the sulphonate oil with much more sulphur and phos in the anti-wear capability .


Link

 

[Gokhan]

Originally Posted By: btanchors
Note that the additive package has changed, but very similar to Mobil 1 0W-20 SN, in that it uses a combination of Calcium and Magnesium for detergent additives. I am also shocked at the high TAN!

The reason magnesium is used is that it has a higher TBN retention. If an oil needs to last more than, say, 10,000 miles, chances are that it needs to have magnesium. Magnesium has some possible corrosion and wear issues but it's used in HDEOs (which are always extended drain) and extended-drain gasoline-engine oils. The high initial TAN is also characteristic of the Mg.

The initial TBN by the way translates little into oil life if TBN retention is not good. Mg is a known detergent/base to increase TBN retention and hence oil life.

 

[buster]

Thanks for the link. You're right, Tbn retention is more important.