Moly vs non-Moly oils

[SR5]

@SR5

So what's the bottom line?
Why do engines sound VERY smooth with moly and most if not all Japanese recommended oils have it?

Is it because it clings better? I know it's a pricey additive and not just for Japanese engines. I've read about the smoothness reports in several different car websites including Ram, etc. Basically you have a much better chance (i.e. not always) of making things quieter with moly than without.

btw, do you know Shannow? j/k
I hear that sometimes. You moved here from ... do you know xyz? lol

Hey Mate,

I believe the MolyDTC that is added to the oil forms MoS2 on the surface of the metal parts. Molybdenum disulfide is a sheet like structure, that bonds strongly in the plane of the sheet, but weakly between the sheets. So in that respect it acts like graphite and can be used as a dry lubricant and the sheets easily slide over the top of each other. It’s also fairly chemically stable in the harsh environment of the engine.

So in boundary lubrication conditions, where the oil doesn’t provide total surface separation, the sheets of MoS2 slide over each other, reducing friction and decreasing wear. Any reduction in friction should offer a small increase output power, a small reduction in fuel consumption (better economy) and a probably a quieter engine. This is probably what attracts some manufacturers. Certainly Nulon oils in Australia are big on the benefits of adding a big slug of moly to their oils.

But I have also noticed that some of the original Euro A3/B4 long life formula had no, or very little, moly in them. But this appears to have changed recently. This M1 0W40 VOA shows 80 ppm Mo.

Mobil 1 0W40 Euro VOA

From the mart of wall. My baseline for a UOA coming up in a few mos. to compare how this looks vs. the Liquimoly oils I've been using/abusing in my Sportwagen.

bobistheoilguy.com

Yeah, I exchange emails and PM with Shannow, but I have never met him in person. He is a very smart man, and a nice guy.

 

[OVERKILL]

Hey Mate,

I believe the MolyDTC that is added to the oil forms MoS2 on the surface of the metal parts. Molybdenum disulfide is a sheet like structure, that bonds strongly in the plane of the sheet, but weakly between the sheets. So in that respect it acts like graphite and can be used as a dry lubricant and the sheets easily slide over the top of each other. It’s also fairly chemically stable in the harsh environment of the engine.

So in boundary lubrication conditions, where the oil doesn’t provide total surface separation, the sheets of MoS2 slide over each other, reducing friction and decreasing wear. Any reduction in friction should offer a small increase output power, a small reduction in fuel consumption (better economy) and a probably a quieter engine. This is probably what attracts some manufacturers. Certainly Nulon oils in Australia are big on the benefits of adding a big slug of moly to their oils.

But I have also noticed that some of the original Euro A3/B4 long life formula had no, or very little, moly in them. But this appears to have changed recently. This M1 0W40 VOA shows 80 ppm Mo.

Mobil 1 0W40 Euro VOA

From the mart of wall. My baseline for a UOA coming up in a few mos. to compare how this looks vs. the Liquimoly oils I've been using/abusing in my Sportwagen.

bobistheoilguy.com

Yeah, I exchange emails and PM with Shannow, but I have never met him in person. He is a very smart man, and a nice guy.

Excellent summary.

One of the other reasons an oil may not have moly is because the blender is using something else. Ravenol uses a Tungsten-based FM and Castrol and a few others have used Titanium ones. I've not seen comparative testing of these different options, but since all three are featured in products that pass the same suite of approvals, I expect it is safe to assume that they all function similarly.