MDS vs ECO

[Hd74ica]

Hello

I have 8000 miles on my '18 2500 6.4 4x4 with 4.10 and should know the answer to this but don't. How do I know when my Hemi MDS system kicks in? Is the MDS activated when ECO displays in the EVIC? Understand fires on only 4 cylinders when in MDS. Maybe I'm wondering if MDS and ECO are one in the same. Thanks.

David

 

[Deki]

Mds and Eco are the same yes.

 

[Wahrsuul]

Some say they aren't the same. I'm not convinced either way. The owner's manual is vague as is most of the info online. I know that when I deactivate MDS - using the shifter or the T/H button - the Eco (Fuel Saver in my '09) light doesn't come on anymore, so how can they not be connected?

On another note, I didn't think the HDs had MDS?

 

[olyelr]

Some say they aren't the same. I'm not convinced either way. The owner's manual is vague as is most of the info online. I know that when I deactivate MDS - using the shifter or the T/H button - the Eco (Fuel Saver in my '09) light doesn't come on anymore, so how can they not be connected?

On another note, I didn't think the HDs had MDS?

The eco light is basically telling you its in mds mode. Thats all.

The hd’s with the 6.4 have mds. On the hd’s, when you switch into tow haul mode it will not come on. Also, if you switch the gear selecter to where can read the actual gear number on the dash (instead of just “D”), mds will not come on.

 

[busterbrown]

On another note, I didn't think the HDs had MDS?

They certainly do. You can feel it when MDS activates with noticeable drone, especially with an aftermarket exhaust.

 

[Wahrsuul]

Ah, ok. I only recall reading about the early HD's with the 5.7. Never looked into the 6.4 model.

I've seen the "Eco vs MDS" discussion several times on the forum and there's little agreement. Some say it's connected to MDS, some say no.

 

[Bock]

I am on the side that it's one of the same, becuase the the ECO light dose not come on when you are in the H/T mode even when you let off the gas going down the road and the RPM's drop.

 

[turkeybird56]

I believe, skerry, that MDS and ECO mode are related. Whether or not the light indicates, who knows. But I also know when driving down a highway, I switch to Tow/haul eco light goes off immediately, and I can feel the vehicle departing MDS. Same if I manually select gear, and immediately MDS goes off and eco light also. There was somebody on this forum who works for FCA> Cannot remember name, maybe he cold chime in. But WTH, either it is on or not. Even with stock muffler, I can tell when it is on, just all IMHO.....

 

[TonyMM]

On the 5.7l ECO and MDS are related but not the same.

If MDS, then ECO.
If ECO, either MDS or a currently high mpg (cruising with a light foot etc...)

 

[Krackle]

Dumb question, when you do the gear selector thing and put in 8 to stop mds from kicking in, does transmission stop at 7th gear or does it go into 8th gear?

 

[pacofortacos]

Goes to 8th, it goes to the highest gear you have showing. Show 7 it will only go to 7th.

 

[pacofortacos]

On the 1500 and at least my 2016, ECO and MDS are not connected in any way.
On mine ECO means you are driving in a fuel efficient manner - 4 or 8 cyl.
MDS is 4 cyl mode.
I have seen
ECO on MDS off
ECO on MDS on
MDS on ECO off - rare though.
I can hear and feel it in my 16 Outdoorsman.

Tow/haul does not disable ECO or MDS, only ERS disables them on my truck.

Whether the HD's or other years are slightly different, I do not know.

 

[Wahrsuul]

On my '09 1500, using T/H or the manual shift mode turns off MDS and the Fuel Saver light (they changed it to Eco in later years) stops coming on so I'm inclined to believe it has to do with MDS.

I can usually telll when MDS has kicked in, and I have a PC I keep in Eco mode so it's easier for me to get the FS light on and get into MDS as soon as possible. Doesn't work well around town, but I do the best I can.

 

[pedersen_tim]

When im cruising around town my eco light comes on and off and i never hear my mds kick on. I have an exhaust cutout and when its open and the mds turns on you can definitely hear it for sure. Tow and haul wont turn off mds but selecting the gears on the steering wheel will for sure. Just put it in 8th and drive, the trans will shift like it normally would.

Sent from my SM-N960U using Tapatalk

 

[boxofrokx]

I believe you are wrong. A quote from link below (2009 FCA), 'When MDS is operating, it is indicated by a “Fuel Saver” readout in the vehicles Electronic Vehicle Information Center.' In later trucks they changed it to ECO. http://media.fcanorthamerica.com/newsrelease.do?id=8414&mid=

I will believe FCA until I see something more convincing.

 

[pacofortacos]

Might be that way for the 09 model year, definitely is not that way on the 16 1500.

 

[boxofrokx]

I have had a 2o1o 1500 and 2o15 2500. It works as described in both. So, with all do respect, and remember I said 'with all do respect', I'll believe FCA and my own experience until something more compelling come along.

 

[boblonben]

I believe, skerry, that MDS and ECO mode are related. Whether or not the light indicates, who knows. But I also know when driving down a highway, I switch to Tow/haul eco light goes off immediately, and I can feel the vehicle departing MDS. Same if I manually select gear, and immediately MDS goes off and eco light also. There was somebody on this forum who works for FCA> Cannot remember name, maybe he cold chime in. But WTH, either it is on or not. Even with stock muffler, I can tell when it is on, just all IMHO.....

The answer is yes, and no. You can have ECO and not have MDS engaged in a light throttle situation where the sensor has not yet activated the MDS mode, but the difference is very, very small. So generally mds and eco are almost the same.

 

[RobRoy]

I sound like a freaking Subaru coming down the highway in my 6.4 with muffler delete in MDS

 

[olyelr]

I sound like a freaking Subaru coming down the highway in my 6.4 with muffler delete in MDS

An 18 year old kids subi, or grandmas subi? lol