FM chemistry and MDS

[SubieRubyRoo]

So if your MDS is “noticeably smoother” using the premium plus 0w20, that tells me that the supercar 0w40 additive pack in OVERKILL’s special blend is not the variable that is smoothing out the “MDS rumble”.
With that said, yours is “noticeably smoother” while he described his as “imperceptible”. It’s possible that the difference between smoother and imperceptible is the difference between his Grand Cherokee with its 6.4 vs our Rams with the 5.7l. As for his Ram, it could be the difference between our older body style without dampers vs his with the dampers.

I need a cup of coffee. My brain is working too hard on a Saturday morning.

How do you know that the FM that could be resulting in the change isn’t the same between the two oils? Whatever is causing it may be more present in the SuperCar blend, but if there is sufficient in the Premium Plus to still get similar or almost-similar results. The only real way to tell would be for Skippy to try the SC at some point and see if the rumble is further reduced.

 

[HemiBenny]

How do you know that the FM that could be resulting in the change isn’t the same between the two oils? Whatever is causing it may be more present in the SuperCar blend, but if there is sufficient in the Premium Plus to still get similar or almost-similar results. The only real way to tell would be for Skippy to try the SC at some point and see if the rumble is further reduced.

You're correct, there's no way to tell unless extensive experimentation is carried out. For that, OVERKILL would need to use the Premium Plus and Skippy would have to use the special blend that OVERKILL had made to see if they experience an improvement on Skippy's part and a slight reduction on OVERKILL's part.
There again, as I mentioned, the difference in their perception of the "MDS rumble" being reduced to the levels they experienced could also "Possibly" be the difference in the vehicle structure. The difference is the new Ram with Dampers vs. the old Ram without and also the Grand Cherokee SRT8 with a 6.4l vs an older Ram with a 5.7L, all completely different animals.
The Critic had previously stated this about his Ram, "To be fair, mine is almost unnoticeable as it currently is.", and as OVERKILL mentioned to him, his Ram has the frame-mounted Dampers that Skippy's is not equipped with. Right there, OVERKILL mentions a variable when it comes to the Ram vs Ram MDS rumble.
So using The Critics experience, a Ram with dampers is almost unnoticeable as is, while the older Ram is very noticeable,... I know this because I drive one. Therefore the same amount of reduction in "MDS rumble" using either oil may take the new Ram to "imperceptible" while taking the older Ram to "noticeably smoother" with the dampers and structure being the variable causing the difference in perception.
I guess what I should have stated is that it is "possible" that the special blend with the Supercar 0w40 additive is not specifically needed to achieve the "same level" of reduction in "MDS rumble".
Either way, you're correct, I really don't know for sure, I'm just forming an opinion based on what I've read and my thoughts on the differences in vehicles. More experimentation is called for.

 

[OVERKILL]

You're correct, there's no way to tell unless extensive experimentation is carried out. For that, OVERKILL would need to use the Premium Plus and Skippy would have to use the special blend that OVERKILL had made to see if they experience an improvement on Skippy's part and a slight reduction on OVERKILL's part.
There again, as I mentioned, the difference in their perception of the "MDS rumble" being reduced to the levels they experienced could also "Possibly" be the difference in the vehicle structure. The difference is the new Ram with Dampers vs. the old Ram without and also the Grand Cherokee SRT8 with a 6.4l vs an older Ram with a 5.7L, all completely different animals.
The Critic had previously stated this about his Ram, "To be fair, mine is almost unnoticeable as it currently is.", and as OVERKILL mentioned to him, his Ram has the frame-mounted Dampers that Skippy's is not equipped with. Right there, OVERKILL mentions a variable when it comes to the Ram vs Ram MDS rumble.
So using The Critics experience, a Ram with dampers is almost unnoticeable as is, while the older Ram is very noticeable,... I know this because I drive one. Therefore the same amount of reduction in "MDS rumble" using either oil may take the new Ram to "imperceptible" while taking the older Ram to "noticeably smoother" with the dampers and structure being the variable causing the difference in perception.
I guess what I should have stated is that it is "possible" that the special blend with the Supercar 0w40 additive is not specifically needed to achieve the "same level" of reduction in "MDS rumble".
Either way, you're correct, I really don't know for sure, I'm just forming an opinion based on what I've read and my thoughts on the differences in vehicles. More experimentation is called for.

And it's also important to keep in mind here that MDS had absolutely no bearing on my suggestion to Dave that @High Performance Lubricants could produce a 0W-20 with a full-SAPS Euro additive package. This was just a side effect of my switch to HPL, I wanted the Euro additive package for the higher levels of AW additives.

 

[HemiBenny]

And it's also important to keep in mind here that MDS had absolutely no bearing on my suggestion to Dave that @High Performance Lubricants could produce a 0W-20 with a full-SAPS Euro additive package. This was just a side effect of my switch to HPL, I wanted the Euro additive package for the higher levels of AW additives.

Absolutely! I completely understand your reasoning behind the suggestion and I think that it’s a great one. You know, there’s usually a negative connotation associated with the words “side effect”, but it’s nice to have positive side effects from time to time.

 

[Skippy722]

Figured I’d update since I now have @OVERKILL’s blend in my truck. My highly (un)scientific vibration sensors (my hands and butt) say the MDS rumble is further reduced.

My oil pressure was also slightly different. Cold start (it was 35F yesterday) generally resulted in 60psi, and hot idle (195-205F) resulted in 30psi. Yesterday it settled to 56psi cold and 37psi hot. Used the same Mobil 1 filter I always use. Maybe it was just a fluke, I’ll check again if I go out today.

 

[GMBoy]

I figured I'd give this a while to see if it persisted before putting together a thread on it.

As everyone knows, I swapped out two very high quality synthetic oils (Ravenol SSL 0W-40 and M1 EP 0W-20) in the Jeep and RAM for @High Performance Lubricants Super Car oils, both with Euro additive packages. However, we've owned many engines with MDS starting with our 2006 Charger R/T, 2014 Charger SRT-8, 2016 Grand Cherokee SRT...etc.

I've owned 3x SRT Grand Cherokees and they all have the same "rumble" from the MDS because you are inches away from the engine and it isn't very well insulated, so it's very easy to discern when it is on the MDS or not. The RAM, since it has active dampening (frame mounted harmonic devices designed to counteract the MDS rumble) has always been vastly less perceptible with only the exhaust note really being the cue, since it has a Borla system on it, which isn't exactly quiet, and the note changes when it drops into 4-banger mode.

I've run several different oils in my SRT vehicles including the Pennzoil SRT 0W-40, Mobil 1 FS 0W-40 and of course the Ravenol mentioned above. Every single one of them behaved the exact same, which one would expect.

So, you can imagine my surprise when, after I put in the HPL oil that the MDS became imperceptible on the Jeep. I mean completely. You cannot tell if it is on the MDS or not, since you can't hear the exhaust (factory exhaust). I was initially doubting myself on the matter, thinking well, this isn't possible. However, upon changing it in the truck, there was also a difference, even though you couldn't really feel much in the first place. So, after driving the Jeep for a while now with this oil, and this continuing to be the case, I've concluded that it must be the FM chemistry. I mentioned it to Dave and he kind of laughed and said "well, nobody is going to believe you" but at this point, I was like, well, I'm going to share it anyways.

I'll stress that nothing else has changed. Engine runs the same, sounds the same, oil pressure is the same, only difference appears to be the MDS operation.

Unfortunately, I don't have a VOA of this oil and I suspect some of what Dr. Rudnick has put together here is highly proprietary (@MolaKule could perhaps speculate) so I don't think we are going to get an answer on that. I do know that (since Dave is very forthcoming) that they use a variety of FM chemistries together, as certain combos have extremely good synergies, but it depends on the overall formulation as to what works best, which can only be determined with testing, which they of course perform. We are talking dimer moly, trimer moly and tungsten. Not sure if they also use titanium or not, I didn't ask. But basically, it is a complex FM development that is undertaken to determine what works best with a given base oil and additive package chemistry.

I would be very interested if somebody else with a 6.4L that has MDS would buy the same oil and see if their results are the same as mine.


EDIT: Per Wayne's request,
FM = Friction Modifier, these are compounds that reduce the coefficient of friction on surfaces, reducing drag and improving efficiency
MDS = Multiple Displacement System. This is a cylinder deactivation system that, using a mechanism inside the lifters, disables 4 of the 8 cylinders to improve economy

I respect you on this forum and I can honestly say that your description of the issue is believable to me - not like some posts saying that their engine is now louder because they put in mobil 1 LOL!!!!!

 

[Skippy722]

Same thing, hot idle is now 35psi, was always 30 previously cruise is still 49-50.

Ignore the gas cap light I’ve not been bothered to fix.

 

[The Critic]

Same thing, hot idle is now 35psi, was always 30 previously cruise is still 49-50.

Ignore the gas cap light I’ve not been bothered to fix.
View attachment 147161

More dependent on your filter than the oil. With an oil temp of 212F, I’m at 29 psi with a fresh fill of HPL Euro No VII 5W20 and an ACDelco Ultraguard. Normally it is 32-34psi with a Mopar filter.