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in the process of doing research, found moly as an additive touted to be pretty good, and in oils I've used with moly the results have been good as well regarding wear metals.
seems redline has a LOT of moly and just as much zddp as amsoil's zrod. def next on the list to try, though it is quite pricey
This was a fantastic project, and just the kind of information I have been searching the internet for.
There is just one point of clarification I hope golgol13 can address. (And I apologize if this has already been discussed; I haven't read all the posts in the whole thread.)
If I understand the basic principles underlying the testing method, the volume (measured as height in the tubes) of condensates of particulate matter left in the oil samples was measured after the samples were aspirated with a syringe from oil that had passed through the filters and the condensates were allowed to accumulate under gravity for 48 hours.
If that is so, shouldn't the volumes of oil in the samples have been the same at the start of the 48 hours? The assumption being that the only difference among the samples is the amount of particulate matter left behind, not the volume of oil that it is suspended in?
In the pic showing all the tubes lined up, it seems like the volumes of sampled oil weren't equal. The third tube from the left, for example, seems to have about 30-40% less material in it than each of tubes #1, #4, and #5.
in the process of doing research, found moly as an additive touted to be pretty good, and in oils I've used with moly the results have been good as well regarding wear metals.
seems redline has a LOT of moly and just as much zddp as amsoil's zrod. def next on the list to try, though it is quite pricey
Letsgetthisdone is exactly right - moly compounds are a friction reducer (friction modifier). You would think that a friction reducer would also be a wear reducer, and it is, but there are better wear reducers than moly (like ZDDP). Moly compounds have been around for a long time for use in motor oil and as I remember the problem in the early years was that they were added as small particles which would get gradually filtered out by the oil filter. But that problem I'm quite sure has been solved in more recent years because of the need for better fuel economy - the main-stream oils use friction reducers to help the OEMs meet fuel economy targets. You will notice that motorcycle oils (for wet clutch bikes) never have moly in them because it would make the clutch too slippery - I think - or it might be some other reason!
I've noticed that the different high-performance and racing oils have different philosophies about whether to use ZDDP and moly or just ZDDP. As far as I know, Swepco and Mobil1 racing oil for example, use a lot of both.
So, back in 2010, I asked John Cannella this question: "What is the reason why you don’t put friction modifiers into Penn Grade 1 oil?" John is or was the chemist at Brad Penn. Here's what he wrote back to me:
"There is a modest amount of friction modifier built into the main detergent inhibitor package that is utilized in our PENN GRADE 1 oils which affords favorable sequence VI-6 fuel economy test results in ILSAC SAE grade 10W-30. A formulator may add additional friction modifier to lighter oils such as 5W-20, and 5W-30 due to tougher test requirements for these grades. Additional friction modifier added to the 20W-50 grade would offer no benefit in the sequence VI fuel economy test because the kinematic viscosity of this grade is much too high to attain fuel economy benefits no matter how much friction modifier is added, similarly for grades 10W-40 & 15W-40. Friction modifiers compete for surface area, too much and anti-wear performance may be compromised."
"Friction modifiers are relatively new to engine oil formulations, before the advent of CAFÉ requirements very few if any engine oils included them. ZDDP is a time proven additive that has several functions: Antiwear agent due to the formation of chemical reactions on metal contacting surfaces resulting in a lower shear rate than the base metal, Antioxidant, Rust and Corrosion Inhibitor – acts as a peroxide inhibitor which is a precursor to carboxylic acid formation. Engine oils will also employ dispersants and detergents to combat sludge, varnish and neutralize any acids that are formed. The sole function of friction modifiers is a very modest gain in fuel economy. Friction modifiers have a legitimate place in engine oils and have helped save many gallons of petrol, not to mention many dollars for car manufacturers helping them meet Corporate Average Fuel Economy limits (not sure what the fine is today), hence the drive towards lighter oils 0W-20 and 5W-20."
So basically my answer to your question is: I don't know but it's an interesting subject!
Last edited by Talonboost; Oct 2, 2015 at 03:40 PM.
it sounds like moly would be useful in lighter weight oils, but not heavier ones. it was added to light weight oils so they could be utilized for fuel economy purposes. benefit for our cars? possibly, but only if running the lighter oils.
if you are running a heavier weight, then no.
moly will help with MPG due to being able to run the lighter weight oils.
zinc is all-around a good additive (in my opinion, crucial). it works well with any oils. it serves a different purpose than moly. it will help your engine last longer by keeping the parts and oil cleaner (i'm simplifying here).
if you need to run a lighter oil, due to clearance issues, then moly may not be such a bad thing. if you are running heavier oil, because of looser tolerances, then it's not going to help at all.
i'd think all lighter-weight oils would have a substantial amount of moly in them, otherwise they couldn't get away with being so thin. is there a max limit? is there a point when more is too much?
The assumption being that the only difference among the samples is the amount of particulate matter left behind, not the volume of oil that it is suspended in?
In the pic showing all the tubes lined up, it seems like the volumes of sampled oil weren't equal. The third tube from the left, for example, seems to have about 30-40% less material in it than each of tubes #1, #4, and #5.
You are correct. Not sure why the volume of oil between each tube appears to be inconsistent. The same syringe was used each time (with appropriate cleaning between each sample) and the same volume of fluid was drawn into each tube with each sample.
This of course could potentially invalidate the test, as a differing volume of liquid in each sample would return x^y amount of particulates with x being the oil and y being the particulates per sample.
That's how I read it too. One crucial sentence from John is: "Friction modifiers compete for surface area, too much and anti-wear performance may be compromised." In other words, ZDDP and friction modifiers and other additives are all competing for the same space on the surfaces of the moving parts. So their effects are not exactly additive to each other, one may partially exclude another.
Even if you don't have much moly in the oil, there is still such a thing as "too much" ZDDP. According to Brad Penn, that works as described in this tech letter on their web site: http://www.penngrade1.com/CMSFiles/F..._BRAD_PENN.pdf
This is a 2 page pdf and you pretty much have to get down to page 2 to see the explo for how there can be too much.
Even if you don't have much moly in the oil, there is still such a thing as "too much" ZDDP. According to Brad Penn, that works as described in this tech letter on their web site: http://www.penngrade1.com/CMSFiles/F..._BRAD_PENN.pdf
This is a 2 page pdf and you pretty much have to get down to page 2 to see the explo for how there can be too much.
I find that interesting seeing how Brad Penn had the highest amount I've seen, other than a few motorcycle oils. I guess it takes a ton to be too much.
Originally Posted by golgo13
You are correct. Not sure why the volume of oil between each tube appears to be inconsistent. The same syringe was used each time (with appropriate cleaning between each sample) and the same volume of fluid was drawn into each tube with each sample.
This of course could potentially invalidate the test, as a differing volume of liquid in each sample would return x^y amount of particulates with x being the oil and y being the particulates per sample.
I haven't read that story in a long time. Maybe the difference had to do with some oils breaking down or burning off more than others?
interesting point about too much additives. jon@tre once described oil like salad dressings, where all the good stuff is the stuff in the base dressing, not necessarily the dressing itself. obviously not a perfect analogy. it does seem that moly helps with cold start wear, which is where most of the wear comes from - curious how that will be for a car that is autoxed just about every time it is driven. i'm not saying i'm switching from an oil that has high moly and low zddp, just trying one that has more moly.
zrod is a relatively high zddp relatively low moly oil; i think the SSO has about double the moly, but less zddp, and redline has a huge amount of moly and roughly the same amount of zddp that zrod does. will give them all a test next year and post the UOAs
I find that interesting seeing how Brad Penn had the highest amount I've seen, other than a few motorcycle oils. I guess it takes a ton to be too much.
Well, I think Brad Penn has the amount set to what they think is the "optimum" where adding more would make it worse.
The Mobil1 info on Mobil1 Racing oil (race only) still pushes the importance of ZDDP. Here is a chart they show for zinc levels of their 6 "raciest" oils. This is 2015 info, from here: https://mobiloil.com/~/media/amer/us...guide-2015.pdf
This also mentions "Friction Reduction" but I don't see where they elaborate on what they do to get friction reduction.
Last edited by Talonboost; Oct 2, 2015 at 07:20 PM.
Interesting discussion on moly additives. I guess I'll add that molybdenum is not simply being dumped into the oil in elemental format. It is added as a compound like ZDDP. There are apparently two common anti-wear moly compounds. The one that most people are aware of, molybdenum disulfide, is actually not a good motor oil additive because it will not remain in suspension. The compound that does work is molybdenum trialkyldithiocarbamate or molybdenum dialkyldithiocarbamate. It chemically bonds to the metal surfaces, althought I doubt it bonds to any metal surface, e.g., steel, aluminum, brass. I need to do a bit of digging to figure which metals it does bond with. At any rate, these are likely the moly additives that are being used in modern energy efficient motor oils. If it truly does bond to surfaces effectively, it sure seems to me that it would be a useful additive even in the high performance motor oils that we use.
Interesting discussion on moly additives. I guess I'll add that molybdenum is not simply being dumped into the oil in elemental format. It is added as a compound like ZDDP. There are apparently two common anti-wear moly compounds. The one that most people are aware of, molybdenum disulfide, is actually not a good motor oil additive because it will not remain in suspension. The compound that does work is molybdenum trialkyldithiocarbamate or molybdenum dialkyldithiocarbamate. It chemically bonds to the metal surfaces, althought I doubt it bonds to any metal surface, e.g., steel, aluminum, brass. I need to do a bit of digging to figure which metals it does bond with. At any rate, these are likely the moly additives that are being used in modern energy efficient motor oils. If it truly does bond to surfaces effectively, it sure seems to me that it would be a useful additive even in the high performance motor oils that we use.
thanks, i was seeing a few things about there being different forms of moly, but couldn't really see which uses what, etc.
again, i don't think anyone is saying this should take the place of zddp, just in addition to, perhaps moly is really good for engine wear. the only oil i've seen that uses a lot is redline though - will give it a shot soon. sso uses a decent amount but nowhere close to what redline uses - and this is coming from an "amsoil dealer" - just want what's best for my car, though redline is quite expensive. however, i had a liittle more aluminum ppm than i should have on the last run, so we'll see if this is any better
Oct 2, 2015, 02:32 PM
but it's an interesting subject!
