Do you like your MDS?

[dutchman187]

I just spent some time reading. Pretty interesting and counter intuative. I agree that accelerating slowly is bad. Spending 30 seconds at 6 mpg is worse than spending 15 seconds at 4 mpg. Operating the engine at an RPM below peak torque is best. With an automatic transmission we can't choose a high throttle/low rpm shift pattern like the hyper-milers do. My best results are 2600-2800 RPM shifts with maybe 1/3 throttle with the hemi.

All that goes out the window with my previous vehicle, a 3.0 EcoDiesel Grand Cherokee. It made peak torque at 1800 RPM and peak efficiency was around 1650. I could coax 32 mpg in mixed driving from that Jeep with gentle to average acceleration. Diesels don't have throttle plate pumping losses like gassers though.

Really interesting to read this, because I was finding this out myself as I attempt to improve my city mpg. Before, I had been really, really babying my acceleration thinking I was saving gas, but the instant reading would never go up due to never really making it out of 4th before hitting a stop sign of turn. Recently I've been accelerating quicker (not hard), and hit 7th quickly, where my instant mpg goes up drastically if I can maintain 38-41 mph.

 

[MJB4450]

My two cents on MDS.......Had MDS on my Ram and a Challenger. Also had the manual trans Challengers and I got far better mileage with the manual then the auto even though it was rated less. I expect that was true because mileage is determined on an EPA test loop not real wold humans. I never like what I call band aids on engines, put there for the sole purpose of eyewash for the EPA CAFE standards. Some of these band aids might work on a controlled test loop in the shop but real people don't drive test loops and to say people should learn how to drive a particular vehicle a particular way is ridiculous. I drive how I drive. Not how some engineer wants me to drive to try to validate his invention. I also do not like MDS because it obviously causes more stress on the engine. That's why many Challengers, only those with MDS (manual 6-speeds do not have MDS), broke timing chains until they beefed up the timing chain guide. As far as my Ram goes, I tried MDS on and off for extended periods on the same roads, speeds, etc and there was no mileage difference whatsoever. I also noticed no change in current mileage indication when it kicked in. It was kicking in because I felt and heard it. So I ended up doing as other's and right after starting on my way, hit the trans button down to eight. This way I did not have to be annoyed by MDS or worry about the damage the vibrations might have been doing. I now have a V6 Challenger. Nice clean engine. No CAFE band aids at all, and A V6 Grand Cherokee with one CAFE band aid, Stop/Start, which I disabled. But since the Ram was so much more comfortable than the Grand Cherokee, I am looking at trading for a Ram Classic V6 so I can have two of the last vehicles we'll ever see without EPA CAFE standard band aids. As far as better mileage when you get up to speed faster, the Challenger Forum had a big thread on this a while back and I don't remember the details but it was shown by those who are schooled in this, that not lollygagging up to speed does improve mileage, which is fine because that's what I noticed and that's how I drive anyway.

 

[TruckDriver]

I'm in the camp of 'Yes' I actually like MDS since it's not that hard to turn off when I care to - one tap of the gear limit and I'm topped to 8th w/o MDS (or a tap of tow/haul when I want to hold gears longer)

If anything, I wish RAM was smart enough to do GMC style 2/4/6 cylinder deactivation; I'm surprised that they can do that and Ram can't, but then again, the difference may be negligible?

 

[ExcursionDiesel]

Really interesting to read this, because I was finding this out myself as I attempt to improve my city mpg. Before, I had been really, really babying my acceleration thinking I was saving gas, but the instant reading would never go up due to never really making it out of 4th before hitting a stop sign of turn. Recently I've been accelerating quicker (not hard), and hit 7th quickly, where my instant mpg goes up drastically if I can maintain 38-41 mph.

The truck gets lousy mileage at speeds under 30. It you spend too much time accelerating up to speed, mileage goes down. If you speed up quicker (not too quick) then back off and let MDS kick in, you will achieve better economy. Since more distance is covered during light engine load.

Or drive however you like and complain about MDS and MPG. Lol.

What people fail to realize is that EPA Fleet mileage standards are responsible for all the gizmos manufacturers use to increase fuel economy. It is what it is.

 

[Firepower2010]

Totally agree, the MDS system needs work to get it dialed in, as in my opinion it's not tuned right, and again in my opinion in some instances dangerous. Low speed MDS engagement is ridiculous as it makes the truck "hiccup" in the transition from ECo?MDS engagement and full power, I've been in situations where I had butt pucker becuase of this... The system should in my opinion engage under ONLY light load and above 50mph ...

 

[Ram19Va]

I liked it before I got an aftermarket exhaust system lol. Before though on truck it was barely noticeable when it cut on and off.

 

[silver64]

i have never seen a light indicating MDS is active

 

[Rototerrier]

I very much dislike it.

First truck was built 7/18 and had the noticeable sound and feel of MDS kicking in that everyone complains about.

Replacement truck, built 2/19 and behaves and sounds exactly the same. 2 trucks built about 7 months apart from one another and both exhibit the same sucky MDS tendencies. Surges sometimes at low speeds and makes a whoop when transitioning under load.

I do like everyone else and disable it with the limiter.

It's really the one biggest gripe I have about this truck. It's not that big of a deal but if I have to gripe about something, this is it.

 

[Ellisstrong]

I have no issue with mds as it doesn’t feel any different going on or off in my truck...

 

[cotonymopar]

I am fine with mine... no problems...

 

[Gen3CoupeTX]

I don't even notice mine ... Wouldn't even know it engaged if I didn't see that little Eco light come on.

 

[NDRam]

i have never seen a light indicating MDS is active

There is a setting to turn the indication on.

 

[zx3junglist]

I'm still new to the truck so I didn't notice. Is there any kind of dash indicator that MDS is active? Or you just notice by feel?

 

[zx3junglist]

I'm still new to the truck so I didn't notice. Is there any kind of dash indicator that MDS is active? Or you just notice by feel?

nevermind .. reading is fundamental. Just read page 1 and forgot there were more pages.

 

[Biga]

Mine is smooth as butter, the Active tuned mass modules are suppose to get rid of any vibration related to MDS. They look like little cans directly under the front seats mounted to the frame that shake to mitigate any vibrations.

 

[Lights_out]

I absolutely hate it. I hit the gear limit button to disable it every time I get up to speed in the truck. They claimed it was supposed to be less noticable in the 5th gen, but not at all. I feel it kick in, and can't stand the surge upon deactivation when reapplying the throttle.

I've had 2 Hemi Chargers that both had it. Hated it on both of them as well. None of the 3 vehicles exhibited ANY MPG increases with MDS activated vs disabled. It is absolutely useless and it is harder on the engine.

 

[50Front]

Had my truck in two weeks ago and complained about the transition from V4 back to V8 being rough and slight hesitation. I got my truck back and its much much better. I was turning it off everyday and now i don't think about it and don't notice it. I dont have the paperwork so im not sure what they did exactly but i was told on the phone they updated the TCM and PCM.

 

[securityguy]

Had my truck in two weeks ago and complained about the transition from V4 back to V8 being rough and slight hesitation. I got my truck back and its much much better. I was turning it off everyday and now i don't think about it and don't notice it. I dont have the paperwork so im not sure what they did exactly but i was told on the phone they updated the TCM and PCM.

Not sure if I understand what you are talking about based on your comments above. You can NOT turn off the MCDS but you can turn off the Auto Start/Stop feature. You can "trick" the MCDS from turning on if you manually set the gear limit but that is the only way I am aware that it can be temporarily turned "off".

 

[Neurobit]

I must be the outlier. I have never been able to tell when MDS kicks in, so put me in the "like it" category.

 

[securityguy]

I must be the outlier. I have never been able to tell when MDS kicks in, so put me in the "like it" category.

I'm with you @Neurobit ...mine is also super smooth and if it wasn't for the ECO light that I turned on in my settings and the slight change in tone the exhaust makes, I'd never know either.