Another high moly break-in oil.

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Another high moly break-in oil.

We've seen Honda and couple others, now MB.

What is it the Engineers are thinking/reading/doing?

I'm not saying it's a bad thing, I would just like some insight as to the thought process. Is it the young guys? Are they copying each other?

I know we aren't supposed to question these gods, but how much do they know about tribology?
 
Sorry if this is simpleton thinking, but could'nt the high moly content in the factory fill oils be from the assembly lube which has a high moly content?
 
Not simpleton at all! Good thought!!

(Silly me - especially since I've used the (high moly assy lube) stuff myself
pat.gif
)
 
A moly-based assembly lube has been a thory here before.

But the effect is probably the same ... moly (either disulphide or dithiocarbamate) swimming around in the crankcase oil will "plate up" or "uptake" to the motor's stressed spots whether it is introduced as an oil or directly applied to the high-stress bits as a paste during assembly.

It's just that the soluble dithiocarbamate is more stable an won't promote corrosion under certain circumstances like moly disulphide can.

Likewise, high, high copper on GM engines has been discussed similarly. It may be an assembly lube or anti-seize compound applied to parts of the motor at the factory.

dunno.gif


--- Bror Jace
 
I saw a post somewhere on this site that showed a MB list of approved oils and also indicated their factory fills for each current model.
I believe the factory fill was Castrol but am not 100% sure.
 
There are two ways an engine breaks-in. One is where the asperities collide and instantaneously weld and tear away. That, obviously, leaves more (but smaller) asperities and it generates a wear particle that can cause more wear.

The other way is by plastic deformation where the asperities are mushed down rather than torn away. Plastic deformation leaves no jagged edges and generates no wear particle. Moly is a highly polar AW/AF additive that greatly aids break in by plastic deformation.
 
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