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Discussion Starter · #1 ·
Has anyone noticed their truck going to "Eco" mode (as noted by an "Eco" on he bottom left of the instrument cluster)? I have been looking for it, but haven't seen it. Maybe it doesn't go into Eco until it has some minimum number of miles? Mine has 300 atm, so maybe not enough?
 

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Has anyone noticed their truck going to "Eco" mode (as noted by an "Eco" on he bottom left of the instrument cluster)? I have been looking for it, but haven't seen it. Maybe it doesn't go into Eco until it has some minimum number of miles? Mine has 300 atm, so maybe not enough?
Should come on during easy acceleration or coasting, so basically never for me...
 

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This must be the first Ram 1500 you've ever owned........

Has anyone noticed their truck going to "Eco" mode (as noted by an "Eco" on he bottom left of the instrument cluster)? I have been looking for it, but haven't seen it. Maybe it doesn't go into Eco until it has some minimum number of miles? Mine has 300 atm, so maybe not enough?
 

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The eco light just means you're driving in a fuel efficient manner, and the light can be disabled in the Uconnect menu. It can be on or off if the truck is in 4 or 8 cylinder mode and is not tied to MDS function.


Unless they changed it for the 2019s
 

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The Ram is going into the ECO mode already if it is in 8th gear, if it is unmodified
For it to be displayed, you have to change something in the Radio & then it will display on the instrument cluster

If you don't want the MDS to kick in & shut down to 4 cylinders, there are simple things that you can do
1) you can drive around town in 7th gear, that locks out the MDS
2) you can leave your Ram in the Tow/Haul Mode, that locks out the MDS
3) you can drive aggressively in 8th gear & keep the speed above something like 75 MPH on the open road

In 8th gear & driving at 27 MPH, MDS will begin to function, IF you don't press harder on the gas peddle. MDS will continue working unless you press harder on the peddle

As was mentioned above, when your on the highway in high gear, flat ground with the wind at your tailgate or driving down a slight grade, & holding a steady throttle or using Cruise Control, that is when the ECO light will be displayed

There are people in this crazy world that try to drive with the ECO light always on, that is called HYPER Mileing
 

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You can lock out ECO and MDS if you use the +/- buttons and shift to the highest gear (example 8th gear).

You can drive around in town all day in 8th with ECO and MDS OFF if you select 8th as the highest gear.

and you don't have to drive "aggressively" in 8th gear to keep ECO and MDS from coming on.

GTyankee, do you have a HEMI?




The Ram is going into the ECO mode already if it is in 8th gear, if it is unmodified
For it to be displayed, you have to change something in the Radio & then it will display on the instrument cluster

If you don't want the ECO to kick in & shut down to 4 cylinders, there are simple things that you can do
1) you can drive around town in 7th gear, that locks out the MDS
2) you can leave your Ram in the Tow/Haul Mode, that locks out the MDS
3) you can drive aggressively in 8th gear & keep the speed above something like 75 MPH on the open road

In 8th gear & driving at 27 MPH, MDS will begin to function, IF you don't press harder on the gas peddle. MDS will continue working unless you press harder on the peddle

As was mentioned above, when your on the highway, flat ground with the wind at your tailgate or driving down a slight grade, & holding a steady throttle or using Cruise Control, that is when the ECO light will be displayed
 

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Discussion Starter · #11 ·
Thanks for all the helpful answers. Found the setting in uconnect...I guess it defaults to off (though I don't recall the manual saying anything about enabling it in uconnect first).
 

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I was thinking about my old HEMI, 2009 & it would turn on MDS at 27 MPH, that is when it shifted into High Gear. speed limit here is 30 or 35 MPH, town is basically a Speed Trap
It used to irritate me, going from one Stop Sign to the next here in town, with it sounding like someone passing gas while sitting in the bath tub of water
I dropped one gear & the strange noise would quit

I figured both the 5 & 8 speeds have the same top gear , something like .067
 

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Thing I like about the HEMI is that you can actually stay in 8th with MDS off around 45 and it doesn't get bogged down...

unlike my ex jeep cherokee with the v6 3.2. that thing got bogged down so bad had to downshift to 6th all the time.
 

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It seems to be that some trucks come with it enabled and some don't; mine came with it enabled.


My truck will not go into 8th unless I am going at least 55 MPH, and then only under light throttle. Once it hits 50, it goes back to 7th, sooner with any throttle or on an incline. The 8 speed and 5/6 speed both have a 0.67:1 top gear ratio.


It doesn't automatically go into MDS at top gear
 

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I am assuming you have the V8. I think the modern pentastars also have MDS, but I have no idea how they function.

Like what thunderhorse said, "ECO" appears when you are driving in a fuel efficient manor. It almost always means that MDS is engaged, and you're running in 4 cylinder mode to save fuel, but there are times where "ECO" appears and the criteria to engage MDS was not met. I have no personally witnessed this - but I have noticed that sometimes MDS engages/disengages a second or so before or after ECO appears in the EVIC display.

Most V8s (and even V6s) nowadays use cylinder deactivation as a means to save fuel under low loads. Chrysler calls it the "Multiple Displacement System" (MDS). Heres my detailed explanation on it:
MDS is a system that temporarily deactivates 4 of the engine’s 8 cylinders under low load conditions to increase combustion efficiency, and therefore increase fuel economy. The system consists of 4 MDS solenoids, dedicated oil passages within the block, a special camshaft with lobes to allow MDS’s operation, and special lifters on the cylinders that are deactivated (8 in total). The PCM uses oxygen sensor readings to confirm the cylinders are actually deactivated or reactivated, and constantly monitors its performance, taking into account pressure differences based on oil temperature readings.

When the PCM determines conditions are appropriate, it commands the MDS solenoids to engage, one at a time, in the order 1, 4, 6, and 7. The solenoids divert oil flow through dedicated passages inside the engine block into the lifters of those cylinders. Those cylinders use special lifters that have “disconnecting” or locking pins inside of them. When oil pressure compresses the locking pin, it prevents the lifter’s push rod from moving up by decoupling its motion from the camshaft lobes, and thus “deactivating” the cylinder. The transition occurs within fractions of a second, and is closely monitored by the PCM.

The cylinders are deactivated during their compression stroke, where both the exhaust and intake valve are closed. Instead of exiting through the exhaust valve, the combustion gas remains trapped inside the cylinder, where it is constantly recompressed until the cylinders are reactivated. Ignition still occurs in the deactivated cylinders so that all spark plugs wear evenly.

Cylinders are reactivated in the same order. Once reactivated, the exhaust valve opens, allowing the gases to finally escape, and the otto cycle returns to normal.
 

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I am assuming you have the V8. I think the modern pentastars also have MDS, but I have no idea how they function.



The 2016 and newer Pentastars (in the Grand Cherokee and Durango only) have variable valve lift, but the Hemis are Chrysler's only engines with cylinder deactivation. Variable valve lift is only on the PSU version of the Pentastar. GM's V8s have had it for some time now and my mom's 2006 Odyssey V6 has cylinder deactivation but I am unsure how it works with overhead cams since there aren't lifters to disconnect. Some Mercedes engines have cylinder deactivation too, but I am unaware of any other companies who have it.
 

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You definitely DO NOT want a newer GM vehicle with AFM (cylinder deactivation).
People complain about MDS in the Hemi........You'd end up trading a Silverado or a Sierra its so bad.

Who wants a V8 only to have it be 1/2 a truck in 4 cylinder mode. Gas saving? NOT.
 

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Mine can maintain 8th gear at 42 mph or slightly less - I am not positive that it is a set mph but rather several conditions that determine it.


On my 16, ECO can be on and MDS is no where in sight, ECO can be on with MDS, MDS can be on with no ECO on.

Most of the time it is ECO on and no MDS with my truck.
I think this is due to the 3.92 gears.
 

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Discussion Starter · #19 ·
Interesting. How are you determining thatDS is engaged or not engaged? I was under the impression that the Eco light was the indicator for that. My 2019 has the 5.7 hemi w/o the start/stop business.
 

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Well, I'm new to Ram ..coming from GMC's continuous Cylinder Deactivation. I turned my ECO light on just to see what it would do and I'm no expert, but my ECO light is coming on when MDS kicks in. If I turn the music off, AC off and really really pay close attention........I can tell MDS has kicked in with ECO light. But unlike GMC, I don't get that horrible drone or body shake. I read that Ram has implemented some things to prevent those two things.

I can almost purposely make MDS kick on. Lone Dutch stated ECO almost always means MDS has kicked on and for my truck........this is the case.
 
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