Decent deal on GC

[camrydriver111]

Originally Posted By: Gokhan
It's not the magnesium that corrodes the lead and some other metals. It's magnesium's inability to keep TAN down if calcium is depleted. Therefore, you may have a strong TBN but TAN may have gone off the roof if calcium is depleted. If GC has plenty of calcium and has a proven record, it's OK.


Where did you discover that Calcium-based additives are better at keeping TAN down?

Interesting blurb from PQIA:

"Although magnesium sulfonate is more expensive than calcium sulfonate, some formulators reportedly prefer its use due to what they feel is improved rust production seen with magnesium sulfonates as compared to calcium sulfonate in diesel engines. Because of this, whereas magnesium can be seen in the spectrographic analysis of diesel engine oils, today it is fairly uncommon to see it at any meaningful level in passenger car engine oil."

http://www.pqiamerica.com/magnesium.htm

It sounds opposite of what you are proposing.

 

[Gokhan]

Originally Posted By: camrydriver111
Where did you discover that Calcium-based additives are better at keeping TAN down?

Read thoroughly. It's a great research paper:

"TBN retention -- are we missing the point?" by Chevron Oronite (PDF link)

 

[camrydriver111]

Originally Posted By: Gokhan
Originally Posted By: camrydriver111
Where did you discover that Calcium-based additives are better at keeping TAN down?

Read thoroughly. It's a great research paper:

"TBN retention -- are we missing the point?" by Chevron Oronite (PDF link)


Thanks.

On a side note do engineers ever do multiple trials to get error bars? Lots of typos too.

 

[edyvw]

Originally Posted By: camrydriver111
Originally Posted By: Gokhan
Originally Posted By: camrydriver111
Where did you discover that Calcium-based additives are better at keeping TAN down?

Read thoroughly. It's a great research paper:

"TBN retention -- are we missing the point?" by Chevron Oronite (PDF link)


Thanks.

On a side note do engineers ever do multiple trials to get error bars? Lots of typos too.

I am still waiting to see all that TAN in 0W30/40 and there are hundreds of UOA around here, especially when it comes to 0W30.

 

[Quattro Pete]

Originally Posted By: edyvw
I am still waiting to see all that TAN in 0W30/40 and there are hundreds of UOA around here, especially when it comes to 0W30.

Agreed. I've taken GC 0w-30 out to 10K miles before. TAN didn't appear to be an issue.

 

[Garak]

Originally Posted By: Gokhan
The actual reason is that not too many people in US trust or care much about Castrol Syntec. It's becoming a clearance product. GC also sells for much less than M1 ($22.97 as opposed to $26.44) at Walmart. It's ironic that it has more PAO and therefore it's more expensive to make.

Maybe Castrol USA is starting to learn from Wakefield Canada, that's all. Castrol has been aggressively marketed up here and is everywhere, and it's always on sale somewhere and has unmatched availability, across all product tiers.

 

[edyvw]

Originally Posted By: Garak
Originally Posted By: Gokhan
The actual reason is that not too many people in US trust or care much about Castrol Syntec. It's becoming a clearance product. GC also sells for much less than M1 ($22.97 as opposed to $26.44) at Walmart. It's ironic that it has more PAO and therefore it's more expensive to make.

Maybe Castrol USA is starting to learn from Wakefield Canada, that's all. Castrol has been aggressively marketed up here and is everywhere, and it's always on sale somewhere and has unmatched availability, across all product tiers.

In Wal Mart, both Castrol and M1 are on sale very often for exactly same price!

 

[SilverC6]

Most EP synthetics rely heavily on magnesium.

Some, like the premium Amsoil product, just load up on more calcium for the cleaning duties.

If magnesium is the culprit, indict M1EP, Castrol Gold EP, and the other top tier oils along with GC.

 

[edyvw]

Originally Posted By: SilverC6
Most EP synthetics rely heavily on magnesium.

Some, like the premium Amsoil product, just load up on more calcium for the cleaning duties.

If magnesium is the culprit, indict M1EP, Castrol Gold EP, and the other top tier oils along with GC.

For a long time I am not taking him seriously, but reason why I replied is that actually someone might take him seriously.

 

[Gokhan]

Originally Posted By: SilverC6
Most EP synthetics rely heavily on magnesium.

Some, like the premium Amsoil product, just load up on more calcium for the cleaning duties.

If magnesium is the culprit, indict M1EP, Castrol Gold EP, and the other top tier oils along with GC.

Yes, I did express my reservations on them as well:

Originally Posted By: Gokhan
Originally Posted By: Quattro Pete
Are there any long term studies showing that magnesium in this product corrodes bearings?

It's not the magnesium that corrodes the lead and some other metals. It's magnesium's inability to keep TAN down if calcium is depleted. Therefore, you may have a strong TBN but TAN may have gone off the roof if calcium is depleted. If GC has plenty of calcium and has a proven record, it's OK.

It depends on how long the OCI is, how much calcium is present, particular engine, and driving conditions. I am not a fan of non-0W-40 M1 grades either because they rely heavily on magnesium. Shell still believes that magnesium is not good, and Pennzoil, Rotella etc. use all-calcium detergents. I give Shell thumbs-up in this area.

Moreover, the base oil of GC doesn't seem particularly higher-quality than M1's because CCS is similar, unless GC NOACK is well below M1's 9%.

 

[69GTX]

The summary of that research paper states that a mix of Calcium and Magnesium additives is probably optimum...get the benefits of both. Mobil 1 and Castrol synthetics are apparently the only 2 major oil formulators using large concentrations of Mg at the expense of lower Calcium. Castrol takes it further than Mobil 1 nearly doubling it from 700 to 1400 ppm. And this particular article was analyzing these additives in diesel engines. Is the analysis fully applicable to passenger car engines?