How important is Moly?

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Jun 26, 2003
Columbus Ohio
I have heard many people on this forum, praise moly in motor oils as the best AW agent seemingly in existance. Several presumably excellent oils do not contain Moly (Amsoil, german castrol,etc). Exactly, how important is it?
I am glad someone asked this. I have no clue either, but itching to know if someone can provide an answer. I also noticed that HD oils like delo/delvac/rotella have no moly (including "golden" delvac 1). Would moly help in selected applications? Which ones? Which engines can benefit from moly? Thanks
The way I understand it......Moly adheres to the metal parts and can fill in microscopic scratches and pits and such (maybe quickening the breakin time because of such). Do the other AW additives do the same? Or am I way off base?
from what I understand, moly helps in bearing wear. I've read that the high amounts of moly in these new 5w-20 weights show that lead wear in UOA to be pretty low. someone correct me if I'm wrong
Well, can't add much to what G-Mann II already stated so well. See this thread for some additional information:;f=21;t=000035 Moly DOTC is an anti-oxidant and has Friction Modification and Anti-wear capabilities. This is a class of organometallic (ash-type) additives. Some formulators/blenders are using some of the newly developed ashless additives (non metallic types) that provide the same function. With the push to lower phosphorus in PCMO's, new additives will be used to replace or supplement the ZDDP, and this is where additive philosophy differs among formulators. Some will continue to use moly DTC and others will opt to use the Borates, Calcium carbonate complexes, and the ashless additives, or a combination of them all. I prefer a three- or four-tier system of AW/EP boundary additives that work at various levels of temperatures, presuures, and other engine conditions.
Just an added note. The combination of Zinc Dithiocarbamate or ZDTC (not ZDDP) with the new borate esters are showing very good numbers in published wear tests. [ August 15, 2003, 02:57 PM: Message edited by: MolaKule ]
Moly: I prefer a three- or four-tier system of AW/EP boundary additives that work at various levels of temperatures, presuures, and other engine conditions. According to your preference would Mobil 1 synthetic satisfy this, and in the regular oils, Pennzoil or Havoline? Just wondering. Thanks & Good Day, Steven
Moly is just one additive in a complex mixture of additives that goes to make up any one oil. If the chemists deicide to go with moly, they do so for specific reasons, and they tailor the overall additive package to obtain the best results using moly. Therefore, just because Brand A oil has moly, and Brand B does not, that doesn't mean that Brand A oil is "better" than Brand B. It simply means it's different. If an oil doesn't have moly, it's FM/AW/EP additive package is designed to function without it. It's that simple.
My answer to this question, months later, is that it's not that important to focuse on ANY one aspect of an oil such as a particular additive or spec. like A3, ZDP/Moly etc. It's the total package as MK and others have been saying all along. G-Mann said it well above. Take this into account: GC, Motorcraft, Amsoil and that Kendall UOA all have ZERO moly and all show some of the best wear out there. [Wink] RL has 500ppm and shows not so good wear. M1R only uses about 80ppm and is used by 70% of NASCAR. Is their something to this? [Cool] [ May 28, 2004, 02:12 PM: Message edited by: buster ]
Originally posted by buster: ... RL has 500ppm and shows not so good wear. ..
Do we really have to go through this crap still. Get real.
Originally posted by Whimsey: Cutehumor, The Motorcraft 5W-20 oil doesn't have Moly in it and it still shows good lead wear in the UOA on this Board. Whimsey
That's because Ford bearings contain no lead, there has been a few threads on this subject here. If there is no lead in the motor, the lead reading will naturally be low or zero. Dave
we've seen some good oils perform well without Moly. My only take is that should you have metal to metal contact within the engine its always nice to have that extra protection barrier. In most daily street driving circumstances you likely dont see much high loading to cause excessive wear, but under harsh driving/aggressive/racing conditions moly likely serves a purpose. I'd always like to have a bit in the mix, much like Mobil1 does, combined with a good oil base you cant go wrong.
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