How much Moly to do any good in an engine?

Status
Not open for further replies.
Joined
May 27, 2002
Messages
3,354
Location
Bolivia
Here is one for Terry or someone who formulates. I recently tested a brand that showed 40 ppm of Moly. I just saw a post of the Redline with 103 ppm of moly. Chevron runs 330 ppm in their Gas Engine oil, but none in the Gasoline and Diesel formulations. 40ppm seems so low compared to the 1200 to 1500 zinc, 1200 to 1300 Phos. and 3000+ of detergent. Does anyone know if 40 ppm does anything other than let you put it on the label?
 
Widman, I've been meaning to address that question for awhile now.

Moly stays suspended in oil until heat atracts and activates it to the metal surface. The excessive amounts is of no use nor concequence until it is used.

As it plates, and is used up being a sacrifial boundary additive, it is then replenished with one of the suspended ones. Now, with this in mind, a small amount is just enough to put a minimal amount on the surface but after a while it will deplete as any other additive, therefore to little does you ok but in longer even maybe extended drains, it will become a mute point as to even having it in there.

From what my chemist has explained to me at one point, that 3% to no more than 5%? (please don't ask me about the % math as I am just repeating this) is all that is needed and that anything more is just a waste and overkill.

So more isn't better but too little isn't as good.
 
So what happens when you see a really high moly number on the analysis? Does this mean that most of the moly did not really adhere to the metal? So if you have two oils that use moly and with all other variables equal, if one shows 200ppm on the test, and one shows 400ppm, would the lower one mean that more moly adhered? And what if you have been using a moly based oil for a while, how do the moly numbers change from the first test to the subsequent ones? Do the numbers for moly drop?
 
So now you've got me looking back at analysis I've done for people on Gas Engines. That would explain a little, but it isn't consistent:
an Engine that went on Chevron (min 330 ppm) from start up. At 800 hours had 254 ppm, at 1300 had 303 ppm, and 2000 hours had 397 (make up oil raises)
Another from startup went from 214 at 600 hrs, to a fairly consistent 320-340 up through 4000 hours where they changed oil.
But another engine, just overhauled that used a brand without moly, has 363 at the first 410 hours.
Another is 295 with 500 hours after a top-overhaul at 23,000 hours, slightly down from their normal 320 range at 1500 to 2000 hours.
All of thouse were Waukesha Engines
But another 6 engines (Caterpillar) that are coninuously in the 320 to 350 ppm range. no noticeble difference between their first change to Chevron and now. Anywhere from 3 to 6 changes per engine.
Still like to know more about the percentages though. 3% equals 50,000 ppm, so maybe there is a decimal mixed up somewhere. As a percentage, the Chevron HDAX would be about .035%, where the 40 ppm I've seen in one brand would only be .004%. Sounds like too little?
 
widman, you got me. My use of Red Line showed slightly more in my 2nd sample than in my first. That would make sense because a lot more of the first sample plated up on the sides of the motor and a lot of the moly in the second batch stayed suspended in my oil.

These results are in the oil analysis "Red Line" thread here on this site.
 
Widman- Isn't 3% 30,000 ppm not 50,000? Am I missing something?
pat.gif
 
Sorry about that. I started to answer both 3 and 5, then shortened my response.
 
I know this is bringing up a REALLY old topic. But, with all of the talk about higher moly in oils such as Mazda 0w20, why not bring this up.

If an engine can only use so much moly to coat, why have a very large amount when it can only plate so much of it? Why have such a large amount when it is just overkill? If 100 ppm or 600 ppm of moly is in a set of oils, and the engine can only use a specified amount to begin with, wouldn't both oils act the same in regards to the amount of moly being utilized from each specific oil?
 
I believe the idea is to have a high PPM concentration in the oil in order to replace the moly which has been plated as it wears off of surfaces.

It IS a 'sacrificial' additive/compound, and does NOT last forever once plated.

Is the above correct MolaCule, or others??
 
MoS2 adheres to metal surfaces when hot and then is washed off at lower temps by the cleansing additives. It's a constant battle between the two.

FYI - Lubro Moly reps e-mailed me and recommend a 4% to 6% solution of MoS2 to the regular oil. I use a 10-oz. / 300ml can for the 5.5-quart sump capacity of several of my vehicles in the extended family.
 
It depends on how the Moly is contained within the additive. Infineum's Trinuclear organic Moly additive is most effective in the range of 75 to 200 ppm of Moly. There was a link to a presentation a while back on BITOG. Since Infineum is a joint venture between Shell and Mobil, it would make sense that they would tend to treat their oils with 75 - 200ppm of the stuff.
 
Well there's this moly stuff and now this Trinuclear organic Moly stuff. Wonder how much Trinuclear organic Moly equals the non-Trinuclear stuff. Then there's oils with low moly but have other additives I guess (Zn) (P) etc. Still confusing.
 
Originally Posted By: Errtt
Well there's this moly stuff and now this Trinuclear organic Moly stuff. Wonder how much Trinuclear organic Moly equals the non-Trinuclear stuff. Then there's oils with low moly but have other additives I guess (Zn) (P) etc. Still confusing.

Well depending upon who you listen to the tri-nuclear type is up to 5 times more effective than other organic moly types.
I suspect use of the tri-nuclear type might also have an advantage in deposit control over the use of higher concentrations of other moly types. Part of my reasoning for thinking so is that Mobil still uses 1,600 ppm of moly in their race oils which begs the question, would such a high concentration be necessary if it were the tri-nuclear type?
 
I guess you just have to figure out how much FM from the moly your engine actually needs to determine which formula to use. Is it possible that the OEM manufacturer's labeled engine oil has the proper balance of additives for their engines? The TGMO label says specially formulated for Toyota engines. I suppose other manufacturers contract with oil companies to achieve the same goal.
 
Originally Posted By: CATERHAM
Originally Posted By: Errtt
Well there's this moly stuff and now this Trinuclear organic Moly stuff. Wonder how much Trinuclear organic Moly equals the non-Trinuclear stuff. Then there's oils with low moly but have other additives I guess (Zn) (P) etc. Still confusing.

Well depending upon who you listen to the tri-nuclear type is up to 5 times more effective than other organic moly types.
I suspect use of the tri-nuclear type might also have an advantage in deposit control over the use of higher concentrations of other moly types. Part of my reasoning for thinking so is that Mobil still uses 1,600 ppm of moly in their race oils which begs the question, would such a high concentration be necessary if it were the tri-nuclear type?


So if tri is up to 5 times more effective, then say 40ppm of tri could be as effective as up to 200ppm of the non tri stuff? Okay I think that may explain some of the UOAs I've seen. I guess the UOAs then doesn't distinguish between the two types.
 
Back to basics:

As explained here regarding friction Modifiers in general:

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729029#Post729029


The modern soluble moly additives are primarily Molybdenum Di-Thiocarbamates, or MoDTCs.

There is the Mono-nuclear type, the Di-Nuclear type, and the Tri-Nuclear type. Which one a formulator uses in an oil and how much depends on a number of factors such as application (daily driver, racing) and cost.

In the Tri-Nuclear moly, the core of the MoDTC molecule has more sulfur in order to create or liberate more MoS2 molecules.

This has three advantages, 1) more sulfur for anti-oxidation and hence sludge resistance and 2) more flat plate MoS2 molecules for friction reduction, 3) less MoDTC is needed for friction reduction over the other types of moly.

Think of the MoDTC molecule as a planar object much like a playing card in a deck of plastic coated playing cards.

The flat plate MoDTC molecules tend to stack themselves so that the top cards are sheared off smoothly, thus reducing friction.

(Other friction reducers reduce friction by virtue of allowing their molecular whiskers to be sheared off, much like a mower blade when mowing grass).

In addition, the sharing of Moly MoDTC components with ZDDP molecular components helps the ZDDP reduce wear.

So, as a formulator I have a choice as to which type and additive level of MoDTC to use for the application.
 
Last edited:
Originally Posted By: INDYMAC
I guess you just have to figure out how much FM from the moly your engine actually needs to determine which formula to use. Is it possible that the OEM manufacturer's labeled engine oil has the proper balance of additives for their engines? The TGMO label says specially formulated for Toyota engines. I suppose other manufacturers contract with oil companies to achieve the same goal.


Exactly.

Depending on the application and the type of MoDTC you use, you test to determine how much friction reduction you really need without overloading your formulation with moly.

Again, formulation is a critical and sensitive balancing act.
 
Last edited:
Originally Posted By: Cooper
So, do we know which oils are using tri-nuclear moly?


Not with any absolute certainty.
However since infinium makes that particular component one can assume that shell and Mobil are using it in their best oils such as pennzoil ultra and likely in the M1 products that have been re formulated lately.
Another clue is that the tri nuclear variant is effective in concentrations as low as 40ppm,so if the voa is showing for example 100ppm moly a person can assume that its the tri nuclear type.
If you look at voa for pp and PYB they have high levels of moly,whereas PU has a much lower concentration.
M1 0w-40 also has a low concentration of moly,under 80ppm if I remember correctly so I am assuming its the tri nuclear type as well.
I don't believe they are supplying it to any other blenders either,so just pennzoil and Mobil have it.
These are only my personal assumptions,so I could be mistaken.
 
Last edited:
Status
Not open for further replies.
Back
Top