FM chemistry and MDS

[OVERKILL]

I have never seen a significant difference in MDS engagement between the factory fill, PP 5W20, M1 5W20 and M1 EP 0W20 on my HEMI. I also do not understand how oil can affect the NVH of this system’s engagement, especially if all of the oils were of the same viscosity and in good condition. @Timmastertech probably has a much deeper understanding of this system than I do; perhaps he has some ideas.

Didn't make sense to me either, but it was very noticeable in the Jeep.

And, as I noted, I didn't notice a difference between any of the other oils I've tried in it either.

Part of the reason for this thread is to figure out WHY. I'm hoping to have somebody (ideally more than one) confirm a similar experience and then we can work on the mechanics of it.

 

[OVERKILL]

I kept the resonator, but that giant suitcase had to go!

Which oil would you like to see used? Should I grab some 0w20 super car or premium or premium plus in 5w20? It currently has Valvoline advanced 5w20 in it, I’ll use a Mobil 1 filter again.

Ideally, the Super Car, because the additive package is the same as what I'm using.

 

[The Critic]

Didn't make sense to me either, but it was very noticeable in the Jeep.

And, as I noted, I didn't notice a difference between any of the other oils I've tried in it either.

Part of the reason for this thread is to figure out WHY. I'm hoping to have somebody (ideally more than one) confirm a similar experience and then we can work on the mechanics of it.

It is possible for the oil viscosity to have a slight impact on the behavior of this system. Is Ravenol more viscous than the HPL product?

 

[HemiBenny]

I have never seen a significant difference in MDS engagement between the factory fill, PP 5W20, M1 5W20 and M1 EP 0W20 on my HEMI. I also do not understand how oil can affect the NVH of this system’s engagement, especially if all of the oils were of the same viscosity and in good condition. @Timmastertech probably has a much deeper understanding of this system than I do; perhaps he has some ideas.

I have used Mobil 1, Rotella Gas Truck, QSUD, and mostly Pennzoil Platinum, all in a 5w20, and have not noticed any discernible difference in mine with these various brand. That’s why this thread has got me interested. I don’t understand what could be making the difference, but I believe that something has happened to get his attention in this way.

 

[OVERKILL]

It is possible for the oil viscosity to have a slight impact on the behavior of this system. Is Ravenol more viscous than the HPL product?

It's possible, I'm sure, there are a number of possibilities here, lol. I'm assuming it may be FM chemistry related, but I could be totally wrong and it is something else. That said, let's take a peek at the specs on the oils I've used:

1. Pennzoil SRT 0W-40:
KV100: 13.7cSt
KV40: 74.9cSt

2. Mobil 1 FS 0W-40:
KV100: 12.9cSt
KV40: 71cSt

3. Ravenol SSL 0W-40:
KV100: 13.25cSt
KV40: 74.4cSt

4. HPL Super Car 0W-40:
KV100: 14.38cSt
KV40: 83.79cSt

So M1 0W-40 was the thinnest, the Ravenol was in the middle and the Super Car is the heaviest. If it was viscosity related, I'd have expected the Mobil oil to increase the sensation relative to the Pennzoil product, but they seemed to perform the same?

 

[bbhero]

You talked about not hearing the MDS with the HPL oil in there right ?

Whereas before you did hear it? With the other oils...

I just want to make sure I'm getting that right.

If I'm thinking about that right. .

I definitely think it can happen that way.

 

[OVERKILL]

You talked about not hearing the MDS with the HPL oil in there right ?

Whereas before you did hear it? With the other oils...

I just want to make sure I'm getting that right.

If I'm thinking about that right. .

I definitely think it can happen that way.

It's more something you feel with the Jeep, not hear, it's a "rumble", and yes, the HPL lube has muted it considerably to the point where most of the time I can't discern whether it is on the MDS or not, whereas before it was quite obvious.

With the truck, there is an audible component, because of the aftermarket exhaust system, while sensation-wise, this is significantly dampened by the frame mount harmonic device designed for that purpose so the results on the truck were far less dramatic, as it didn't have much rumble in the first place, it was very transparent.

 

[JHZR2]

It's possible, I'm sure, there are a number of possibilities here, lol. I'm assuming it may be FM chemistry related, but I could be totally wrong and it is something else. That said, let's take a peek at the specs on the oils I've used:

1. Pennzoil SRT 0W-40:
KV100: 13.7cSt
KV40: 74.9cSt

2. Mobil 1 FS 0W-40:
KV100: 12.9cSt
KV40: 71cSt

3. Ravenol SSL 0W-40:
KV100: 13.25cSt
KV40: 74.4cSt

4. HPL Super Car 0W-40:
KV100: 14.38cSt
KV40: 83.79cSt

So M1 0W-40 was the thinnest, the Ravenol was in the middle and the Super Car is the heaviest. If it was viscosity related, I'd have expected the Mobil oil to increase the sensation relative to the Pennzoil product, but they seemed to perform the same?

Easy then… dump some 20w-50 in there for an OCI and see what happens….

But seriously. This whole matter of oils being louder and quieter has been coming up on here for two decades…. Usually it has been ignored as a “butt dyno” or placebo effect result for years and years by MANY users. But there are two schools of thought.

My only experience with this isn’t in an engine, but differential. My 91 BMW 318 LSD had a whiny diff. Redline, for as great as they claim it is, would get noticably louder pretty quick.

I rebuilt the diff once, swapped it with a well known BMW specialist rebuilt diff and that one had some gear slop and noise too. This was all when the car had around 100k miles. I was about to give up and then I decided to try Specialty Formulations racing gear oil. It made a noticeable difference, and sustained that difference in the same fill for as long as I owned the car, which was another 80k or so until rust got too bad. I found that an unbelievable outcome, but it was something that was very noticeable. I loved that car, it ran wonderful. That noise at speed was the one thing that I couldn’t handle. That SF lube made all the difference in the world. Not sure if @MolaKule can explain why only that product helped, and what the “secret sauce” was since this was like 15 years ago… but that made me a believer that fluid selection and properties play some role….

 

[OVERKILL]

Easy then… dump some 20w-50 in there for an OCI and see what happens….

LOL!

But seriously. This whole matter of oils being louder and quieter has been coming up on here for two decades…. Usually it has been ignored as a “butt dyno” or placebo effect result for years and years by MANY users. But there are two schools of thought.

My only experience with this isn’t in an engine, but differential. My 91 BMW 318 LSD had a whiny diff. Redline, for as great as they claim it is, would get noticably louder pretty quick.

I rebuilt the diff once, swapped it with a well known BMW specialist rebuilt diff and that one had some gear slop and noise too. This was all when the car had around 100k miles. I was about to give up and then I decided to try Specialty Formulations racing gear oil. It made a noticeable difference, and stayed with that difference for as long as I owned the car, which was another 80k or so until rust got too bad. I found that an unbelievable outcome, but it was something that was very noticeable. I loved that car, it ran wonderful. That noise at speed was the one thing that I couldn’t handle. That SF lube made all the difference in the world. Not sure if @MolaKule can explain why only that product helped, and what the “secret sauce” was since this was like 15 years ago… but that made me a believer that fluid selection and properties play some role….

I agree, I'm one of the first to discount louder/quieter observations and "smoother". However, in this case we are talking about a specific characteristic of the HEMI, which is MDS rumble, which is pretty pronounced on vehicles that lack the frame-mounted damper. This is why the DT trucks and newer vehicles have those devices, as it's a pretty readily apparent phenomenon and you don't need a specially calibrated butt dyno to feel it

I was indeed hoping Mola could chime-in here as well with his theory as to why this has happened, because it was quite unexpected. Nothing else changed, it still sounds the same for example, it's just the MDS rumble that has been significantly muted.

 

[Thermo1223]

I was told and so were others than using Rotella 5w40 or Castrol 5w40 or German Castrol(GC) 0w30 didn't have an effect on my ALH TDI(2000 Jetta) in terms of NVH. Oil doesn't affect engine noise at all, it was as previously described all "butt dyno placebos".

I can tell you the GC made that tiny 90HP 4cyl smooth as glass even for a diesel. It revved freely compared to others, sounded better for being a diesel at least. It was just overall more enjoyable. GC was 505.00 approved and being high 30wt probably closer to the 40wts I mention.

So I totally get where you are coming from and frankly believe it is absolutely possible. Shame I can add to the mix by owning a MDS Hemi.

 

[JHZR2]

LOL!

I agree, I'm one of the first to discount louder/quieter observations and "smoother". However, in this case we are talking about a specific characteristic of the HEMI, which is MDS rumble, which is pretty pronounced on vehicles that lack the frame-mounted damper. This is why the DT trucks and newer vehicles have those devices, as it's a pretty readily apparent phenomenon and you don't need a specially calibrated butt dyno to feel it

I was indeed hoping Mola could chime-in here as well with his theory as to why this has happened, because it was quite unexpected. Nothing else changed, it still sounds the same for example, it's just the MDS rumble that has been significantly muted.

I’d argue that a “rumble” is just a similar related physics to noise, smoothness, or any other metric. It has everything to do with what is going on in the engine, which relates to the movement of air and the combustion events happening.

I know when I have it enabled, we can feel the MDS/VCM go in and out on our odyssey, particularly/especially when at speed. But it’s still associated with a torque and combustion related event set. But what manifests itself is still what is translated through mounts, frame, and the vehicle as a whole.

Oils are just one element of the overall “dampening” system…

 

[OVERKILL]

I’d argue that a “rumble” is just a similar physics to noise, smoothness, or any other metric. It has everything to do with what is going on in the engine, which relates to the movement of air and the combustion events happening.

I know when I have it enabled, we can feel the MDS/VCM go in and out on our odyssey, particularly/especially when at speed. But it’s still associated with a torque and combustion related event set. But what manifests itself is still what is translated through mounts, frame, and the vehicle as a whole.

Oils are just one element of the overall “dampening” system…

Understood.

My point is that a lot of this stuff is highly subjective with respect to noise, "smoothness" and its magnitude and of course human perception and differing degrees of relativity inherent to it, let alone vagueness as to origin. Claims about Oil A being "louder" than Oil B, while Oil A at that point had 8,000 miles on it, there's no way somebody's hearing memory is that good, so they are ultimately comparing used oil to new, not Oil A to B. There is no control as to what constitutes what and to what degree.

On the other hand, MDS is a very specific system that creates a very specific vibration that is significant enough that the OEM is now installing frame-mounted dampeners to mitigate it. It's also specific enough that it is able to be targeted by this purpose-built device. So, the result of its operation (this vibration) isn't something where the perception of it, or even the question of its existence, is subjective in nature like some of these other things are (I'm not saying they aren't valid observations, just trying to characterize here) because it's an acknowledged and understood phenomenon with a mitigation mechanism already employed in some applications.

Your Honda VCM example is a good one, because it's essentially the same thing, the engine cuts off half itself and that's going to create a specific imbalance, which in turn creates a very distinct and repeatable vibration. My hang-up here is on what mechanism is in play with the lubricant that could have an impact on the magnitude of this vibration, because this is highly unusual.

 

[MolaKule]

Easy then… dump some 20w-50 in there for an OCI and see what happens….

But seriously. This whole matter of oils being louder and quieter has been coming up on here for two decades…. Usually it has been ignored as a “butt dyno” or placebo effect result for years and years by MANY users. But there are two schools of thought.

My only experience with this isn’t in an engine, but differential. My 91 BMW 318 LSD had a whiny diff. Redline, for as great as they claim it is, would get noticably louder pretty quick.

I rebuilt the diff once, swapped it with a well known BMW specialist rebuilt diff and that one had some gear slop and noise too. This was all when the car had around 100k miles. I was about to give up and then I decided to try Specialty Formulations racing gear oil. It made a noticeable difference, and sustained that difference in the same fill for as long as I owned the car, which was another 80k or so until rust got too bad. I found that an unbelievable outcome, but it was something that was very noticeable. I loved that car, it ran wonderful. That noise at speed was the one thing that I couldn’t handle. That SF lube made all the difference in the world. Not sure if @MolaKule can explain why only that product helped, and what the “secret sauce” was since this was like 15 years ago… but that made me a believer that fluid selection and properties play some

I looked back at those gear formulations (SDS shown below) and the only thing I can determine that would 'dampen' or reduce noise in some cases was because I used small percentages of high viscosity (> = ISO320) PAOs and esters. I did the same with the engine oil (PCMO and Racing oil) series.

This was before metallocenes and before AN's became widely available and when I had to make my own DI packages from scratch.

I recall having a drive pinion noise in my old '87 Suburban such that when I added those extra HV components to the final formulation, things quieted down.

Base Oils: > 70% Synthesized Hydrocarbons: - One or more of the following: CAS68649-12-7, 163149-29-9, 151006-63-2, 151006-62-1, 151006-60-9, 68037-01-4, 163149-29-9,
Synthesized and Natural Esters < 10% - Proprietary and Confidential.
Additive Package: < 20%; – Proprietary and Confidential.

 

[JHZR2]

My hang-up here is on what mechanism is in play with the lubricant that could have an impact on the magnitude of this vibration, because this is highly unusual.

Well, you’re making my point. Typically we think about mitigating shock, vibration, noise, NVH, etc through rubber mounts, isolation systems, rafts for equipment to be separated on, etc.

Oils are just another knob to turn. Maybe the “lesser partner”, but one that dampens some motion. The resistance to flow, and the hydraulic behavior associated with that is in the mix. The same reason why higher viscosity lubricants have more drag and losses is because it’s harder to move, and results in a greater resistance to motion.

I too would generally believe that a lube with different flow and viscous characteristics in the journal bearings of the engine would have less of an effect on an impulse event as compared to consistent noise or vibration, but it may be an ideal case.

How well do you track MPGs? I suspect yours may drop… if so it sheds more insight. More viscous, maybe some really heavy lubed blended in… who knows?

Next you’ll be a believer in Lucas!

 

[OVERKILL]

Well, you’re making my point. Typically we think about mitigating shock, vibration, noise, NVH, etc through rubber mounts, isolation systems, rafts for equipment to be separated on, etc.

Oils are just another knob to turn. Maybe the “lesser partner”, but one that dampens some motion. The resistance to flow, and the hydraulic behavior associated with that is in the mix. The same reason why higher viscosity lubricants have more drag and losses is because it’s harder to move, and results in a greater resistance to motion.

I too would generally believe that a lube with different flow and viscous characteristics in the journal bearings of the engine would have less of an effect on an impulse event as compared to consistent noise or vibration, but it may be an ideal case.

How well do you track MPGs? I suspect yours may drop… if so it sheds more insight. More viscous, maybe some really heavy lubed blended in… who knows?

Next you’ll be a believer in Lucas!

Thing is, visc is of course temperature dependant. MDS starts working way before the oil is up to temperature and I've never experienced any difference in how it feels regardless of the oil temperature, and thus, viscosity.

I don't think it's viscosity, I think it's something else.

 

[tyman]

I can believe it. In our Odyssey van that calls for 0w20, I tried some 5w30 the last oil change. The engine definitely sounded like it was straining harder and groaning more than the 0w20. I went back to 0w20 the other day for its latest oil change and definitely does not have the louder strained sound anymore.

 

[JHZR2]

Thing is, visc is of course temperature dependant. MDS starts working way before the oil is up to temperature and I've never experienced any difference in how it feels regardless of the oil temperature, and thus, viscosity.

I don't think it's viscosity, I think it's something else.

Well what is the magic something else? I’d still argue a slug of some really heavily basestock similar to what @MolaKule mentioned.

In my diff situation, not only did it reduce whine substantially, but also made the looseness (clunk as power is applied/removed) imperceivable as well. If I’m not mistaken, there’s a basis of this in the design of redline shockproof gear oil, obviously implemented for other reasons.

 

[MolaKule]

My theory is the correct combination of HV PAO's and POE's offer some noise dampening by spreading out (integrating) the Impulse loads. The bulk viscosity of the SPF was still say a 75W90, but that combination seemed to provide an extra 'cushioning' effect.

Redline used a calcium carbonate additive to do the same thing in their ShockProof lubes.

When I removed the SPF gear lubes and replaced them with a Valvoline gear lube of the same bulk viscosity, the noises would reappear.

 

[OVERKILL]

Well what is the magic something else? I’d still argue a slug of some really heavily basestock similar to what @MolaKule mentioned.

In my diff situation, not only did it reduce whine substantially, but also made the looseness (clunk as power is applied/removed) imperceivable as well. If I’m not mistaken, there’s a basis of this in the design of redline shockproof gear oil, obviously implemented for other reasons.

I thought it might be the friction modifier chemistry. They are pretty generous with it, well beyond what any of the other oils I've used have. Now, they do also use, AN's, POE and PAO, but the Ravenol was also PAO-based and I would assume had some POE in it too for that reason.

 

[JHZR2]

I thought it might be the friction modifier chemistry. They are pretty generous with it, well beyond what any of the other oils I've used have. Now, they do also use, AN's, POE and PAO, but the Ravenol was also PAO-based and I would assume had some POE in it too for that reason.

Well then your MPGs should go waaaaay up if it’s just an FM matter. Something tells me they haven’t done so. To passivate such an obvious sensation on the basis of reduced friction (friction of what? do we know what is actually moving or rubbing to cause the rumble?), then friction everywhere would be reduced in kind… and results should be observed in fuel consumption.

IMO it’s some really high viscosity component that isn’t there in other finished blended lines, which provides some cushioning because of its intrinsic strengths. At some point we need to move from generic use of PAO/AN/POE/etc. just because those things are in there doesn’t mean a whole lot. The right ones with the right properties is what matters.