Eco mode

[Bearcatrp]

When my 6.4 goes into Eco mode (rarely) seems the engine isn't running on all cylinders. the manual doesn't cover anything on Eco mode. Feels weird too. Can someone enlighten me on this? thanks.

 

[Boosted Motorsports]

You are correct, that is exactly what is happening. It turns off a few cylinders to save fuel when it doesn't need them.

 

[ramittome]

"Eco mode" as you call it is just the truck letting you know when it's getting the best gas mileage.

What you're feeling is when MESS kicks in. It kills power to half the cylinders, therefore you hear a sound change because it's literally not firing on all cylinders (yes, that was a pun), and is then getting the best gas mileage.

Depending on the type of shifter you have, you can turn it off by putting it into 8th gear, or with a programmer to turn it off completely.

 

[MADDOG]

Yup...ECO mode will bring about MDS, Multi-Displacement System. It "deactivates" 4 cylinders when on.

 

[Thorvald]

Has anyone found a way to force ECO mode on? Wife drives barely 3km to work everyday, I'd love to force it into 4 cylinder mode until needed to get the fuel economy. Don't need 400 horse to go through 2 stop signs up two streets lol.

I know, sound ludicrous since most people want to kill MSD but I love it for saving $$$$.

 

[huntergreen]

No way I am aware of.

 

[Bearcatrp]

I have a 6 speed tranny. Sounds and feels weird when it kicks in. But it rarely kicks in. Love the towing power but miss my 2014 8 speed gas mileage. Thanks folks.

 

[Wahrsuul]

Yup, wish there was a way to get MDS on more often. Why it doesn't idle in MDS.... if they can build cars that shut off at stoplights/idle.

 

[ExpressRules]

Yup, wish there was a way to get MDS on more often. Why it doesn't idle in MDS.... if they can build cars that shut off at stoplights/idle.

May be an issue with having the Hemi idle at such a low RPM on four cylinders without causing excess vibration.

 

[Rampant]

Has anyone found a way to force ECO mode on? Wife drives barely 3km to work everyday, I'd love to force it into 4 cylinder mode until needed to get the fuel economy. Don't need 400 horse to go through 2 stop signs up two streets lol.

I know, sound ludicrous since most people want to kill MSD but I love it for saving $$$$.

You wouldn't want to do that because then you'd be lugging the motor while trying to move a 6k lb truck with 4 cylinders, rather than kind of "coasting" or very low-load condition only as it does when MDS kicks in.

EDIT: Sorry, I thought you had a 1500... so prob closer to a 7k-ish lb truck

 

[Rampant]

When my 6.4 goes into Eco mode (rarely) seems the engine isn't running on all cylinders. the manual doesn't cover anything on Eco mode. Feels weird too. Can someone enlighten me on this? thanks.

Here's an overview of the system out of the book for you:

DESCRIPTION

The Multi Displacement System (MDS) selectively deactivates cylinders 1, 4, 6, and 7, to improve fuel economy. It has two modes of operation:

- 8 cylinders for acceleration and heavy loads.

- 4 cylinders for cruising and city traffic.

The main components of the Multi Displacement System are:

- Unique MDS camshaft.

- Deactivating roller tappets.

- 4 control valves/solenoids.

- control valve/solenoid wiring harness.

 

[Trooper2]

I actually have better gas miliage turning it off. I know it sounds unlikley but its true. I have run without and with it and i consistently get better gas miliage when i turn it off most of the time.

 

[69GWC]

Heard guys post that before.

 

[zogg]

I installed a performance muffler and eco mode sounds crummy. Wish I could turn it off

 

[KansasArt]

I too dislike it. Have 5.7/8 speed. Seems like when it engages and you want to just maintain speed it bogs down like too little rpm or too high of gear. Been turning it off via the gear select. 5 for city & 7 for highway. Of course 8 for extended highway.



Sent from my iPhone using Tapatalk

 

[Trooper2]

Also im not sure turning the cylinders on and off can be good either.

 

[Wahrsuul]

Also im not sure turning the cylinders on and off can be good either.

FCA tested it over lots of miles/cycles and didn't see any appreciable difference in wear. They've been using it on the 5.7 cars for years (Magnum, 300, Charger) with no particular issues.

 

[Trooper2]

I kinda feel like i do not see much benefit from it though.

 

[Lowwhiteram02]

How do you disable the mds? Dont want to use a tuner sisnce i still have a warranty

 

[CTD]

I actually have better gas miliage turning it off. I know it sounds unlikley but its true. I have run without and with it and i consistently get better gas miliage when i turn it off most of the time.

Same hear. I have had mine cut off for 8 months via a custom tune and my gas mileage is about the same if not a little better then when I was running with MDS.