FM chemistry and MDS

OVERKILL

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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
 
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That’s very interesting. I suppose a rumble would be a very good way to describe the audible difference in my 5.7L when the MDS kicks in. I keep the MDS in my Ram turned off by using the +/- button on my shifter every time I get in it because that slight “rumble” just drives me nuts. I know that may be silly to some, but I’m weird that way.
 
That’s very interesting. I suppose a rumble would be a very good way to describe the audible difference in my 5.7l when the MDS kicks in. I keep the MDS in my Ram turned off by using the +/- button on my shifter every time I get in it because that slight “rumble” just drives me nuts. I know that may be silly to some, but I’m weird that way.
Yes, yours being a 2011, it doesn't have the frame-mounted dampeners. I'd be interested if you could try an HPL lube, see if it changes the rumble.
 
I have the passenger car plus in my hemi ram now. I think i will go with the supercar next year. I think mine is quieter with the PC+ over the SRT oil.

I would love to hear from smarter oil guys than me whether the supercar or the PC+ is the oil to run.
 
I have the passenger car plus in my hemi ram now. I think i will go with the supercar next year. I think mine is quieter with the PC+ over the SRT oil.

I would love to hear from smarter oil guys than me whether the supercar or the PC+ is the oil to run.
Super Car is a Euro additive package, at least the one I'm running (in both vehicles). So, more AW additives.
 
It also quieted the piston slap in my '02 Tahoe. Another factor could be the ester and alkylated naphthalene (AN) content. HPL's oils contain a good bit of both. Both ester and AN produce thick tribofilms and act as friction reducers. It's possible that thicker tribofilm, combined with their excellent shear stability, could be aiding a faster transition from boundary lubrication into elastohydrodynamic lubrication, especially when there's no load on the rings (like when MDS is active). The FM chemistry could be synergizing well there, further aiding that transition, and providing a cushion for the piston rattle.
 
Yes, yours being a 2011, it doesn't have the frame-mounted dampeners. I'd be interested if you could try an HPL lube, see if it changes the rumble.
I may just have to do that. I just changed my oil back on the 5th of June, so dumping fresh PP is outta the question. 🤔
With that said, I could order some from HPL and use it on my next oil change and revisit this. I would be willing to do a short oil change interval, just not this short. 🤔😂
 
I may just have to do that. I just changed my oil back on the 5th of June, so dumping fresh PP is outta the question. 🤔
With that said, I could order some from HPL and use it on my next oil change and revisit this. I would be willing to do a short oil change interval, just not this short. 🤔😂
Awesome, appreciate it.

If you might consider, could you think about ordering the 0W-20 (or maybe a 5W-20 variant?) I had blended for me with the Super Car 0W-40's additive package? Just want to keep the variables to a minimum.
 
Awesome, appreciate it.

If you might consider, could you think about ordering the 0W-20 (or maybe a 5W-20 variant?) I had blended for me with the Super Car 0W-40's additive package? Just want to keep the variables to a minimum.
I’ve ran nothing but 5w20 in my truck, so I would have to stay with that viscosity to make sure that nothing has changed except the lube’s manufacturer and add pack when it comes to any discernible difference in my situation. I would be willing to order it with the additive package like you did though.
 
I’ve ran nothing but 5w20 in my truck, so I would have to stay with that viscosity to make sure that nothing has changed except the lube’s manufacturer and add pack when it comes to any discernible difference in my situation. I would be willing to order it with the additive package like you did though.
OK, perfect. It's the additive package that's the key here I think, in terms of maintaining consistency.
 
That’s very interesting. I suppose a rumble would be a very good way to describe the audible difference in my 5.7l when the MDS kicks in. I keep the MDS in my Ram turned off by using the +/- button on my shifter every time I get in it because that slight “rumble” just drives me nuts. I know that may be silly to some, but I’m weird that way.
I did the same in my company 2018 Ram for a while, then just decided to live with it. The newer Rams are much better in NVH when the MDS is activated.
 
That is really odd. I'm struggling to grasp what the oil has to do with it. The MDS system is either on or off.

It's quite noticeable on my 2019 Ram 1500 classic. It was unbearable when I ran a modified exhaust for almost a year.
I’m also wondering how the oil could change anything, but I’m willing to give it a go out of pure curiosity because I don’t believe that Overkill, of all people, would be making this up. Something has happened to get his attention.
As for the exhaust, that’s why mine has stayed stock and the MDS is turned off every time I get in. As slight as mine is, I just don’t like it. I know it’s not hurting anything, but it just annoys me. That system is the only complaint I’ve ever had about my truck.
 
I’ll try it soon, just hit 50% according to the dash on this OCI. MDS is INCREDIBLY noticeable with the flow master muffler I have on mine, as well as the vibration.
The Borla system does a really good job of maintaining a decent note when in 4-banger mode, that was one of the surprises after we bought it. They put a lot of effort into its design.
 
The Borla system does a really good job of maintaining a decent note when in 4-banger mode, that was one of the surprises after we bought it. They put a lot of effort into its design.
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.
 
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.
Premium Plus additive package is more comparable to what you have been running.
 
I believe you one hundred percent.

My lady's 98 Camry sounded stupid loud on Super S and Cam2 semi synthetic oils.

Put Warren Distribution full synthetic in there and it was very noticeably quieter as soon as you started the car.

Different oils can make a difference at times. I have noticed that at times.

Interesting that Cam2 ran extremely quiet in my ol Nissan Altima VQ. And it runs the same in the Acura I have now too.
 
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.
 
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