Poll And Discuss... Turning Off MDS For Long Trip...

Which Is Better For The Engine?

  • Turn It Off

    Votes: 3 21.4%
  • Leave It On

    Votes: 5 35.7%
  • Doesn't Matter, It's Designed To Work

    Votes: 6 42.9%

  • Total voters
    14

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Murphy Slaw

Senior Member
Joined
Oct 7, 2016
Posts
1,509
Reaction score
2,707
Location
Southern Illinois
Ram Year
2016 Bighorn 4X4 Crew
Engine
5.7
This is about engine longevity, NOT gas mileage. I'm curious what brighter minds think.

On a 5 hour Cruise Control trip down I-55 in Mississippi, or a 10 hour ride across I-10 in Texas, which would be better for getting lubrication where it needs to be, and getting maximum miles out of a Hemi?

Or does it matter?

This is about a stock engine, turning it off via the gear buttons.
 

BrianandChrissy

Senior Member
Military
Joined
Jul 11, 2016
Posts
826
Reaction score
477
Location
Buffalo NY
Ram Year
2016 big horn crew cab
Engine
5.7 hemi, vararam CAI
MDS shuts the fuel off to those 4 cylinders, not the oil lubrication. Those cylinders continue to rotate as its impossible to stop them. If i was you, and you plan on leaving the engine stock...i would let MDS engage, and let the next gen engine management do its job.

Sent from my SM-G935V using Tapatalk
 

quietpeen

Senior Member
Supporting Member
Joined
Jul 14, 2010
Posts
25,442
Reaction score
3,905
Ram Year
2021 TRX
Engine
Hellcat
i voted to leave it on
 

WilliamS

Senior Member
Joined
May 3, 2016
Posts
2,638
Reaction score
1,191
Location
Tampa FL
Ram Year
2014
Engine
Hemi 5.7
Im sure over the past decade the MDS Hemi has been out Chrysler has a good idea its ok for the engine. Remember its all still rotating, its still getting oil, and when the cylinders hit a certain temp it turns them back on to keep the block average across to prevent warping.

Let it ride, it has a job to do that they have spent likely millions to get right. Id let it do what it needs to do.

I cant think of any negatives to disabling it other than fuel, but in my 4x4 I get 20mpg on my commute so Ill let it do its job.
 

huntergreen

Senior Member
Military
Joined
Jan 5, 2011
Posts
12,186
Reaction score
25,923
Ram Year
2016
Engine
hemi 5.7
This is about engine longevity, NOT gas mileage. I'm curious what brighter minds think.

On a 5 hour Cruise Control trip down I-55 in Mississippi, or a 10 hour ride across I-10 in Texas, which would be better for getting lubrication where it needs to be, and getting maximum miles out of a Hemi?

Or does it matter?

This is about a stock engine, turning it off via the gear buttons.

murphy, imho, from strictly a lubrication stand point, on or off won't make a difference. engine longevity will neither be enhanced or shortened.
 

powderbrad

Senior Member
Joined
May 22, 2013
Posts
854
Reaction score
152
Location
Edmonton, AB
Ram Year
2011
Engine
5.7
Depends how fast you drive highway.
If 70+ it won't come on anyways so leave it as is
 

Burla

Senior Member
Military
Joined
Apr 28, 2012
Posts
23,108
Reaction score
44,443
Ram Year
2010 Hemi Reg Cab 4x4
Engine
Hemi
If you turn it off with tuner better, but if you have a lead foot I would leave it on.
 

DoubleB223

Junior Member
Joined
May 13, 2017
Posts
26
Reaction score
10
Location
Ky
Ram Year
2017 QC
Engine
Hemi 5.7
I just drove from KY to SC without MDS. The gas mileage did suffer a little but because of the headers and y pipe my tune had to stay. I did down grade to the mph tune on my Diablosport intune i2 and that had helped with the shifting !


Sent from my iPhone using Tapatalk
 

tsielski

Senior Member
Military
Joined
May 11, 2016
Posts
219
Reaction score
338
Location
North Carolina
Ram Year
2017
Engine
5.7 Hemi
I took a 355 mile round trip this past weekend and turned MDS off (with the gear selector paddle switches), and was surprised to get ~ 2mpg better than my best with the MDS normally engaged. And I didn't alter my driving style at all; 70 - 75 mph, sometimes a bit more, and didn't baby the throttle when passing. Since the truck is smoother, on and off throttle, from now on, first thing I do is turn the MDS off after putting it in drive.
Truck is stock w/ 3.92 gears.
 

shane1981

Senior Member
Joined
Dec 25, 2015
Posts
684
Reaction score
231
Location
millington tn
Ram Year
2015
Engine
hemi 5.7
ive been running without mds since my truck had 500 miles on it. im full bolt on jay greene custom tune 93 octane tune 8 speed 3.92 and get 18 in the city and 24 on the hwy so im fine without mds . unless your on a long trip thats mostly flat i cant see mds helping all that much i just took a 12 hr round trip in a 8 speed 3.21 bone stock truck and only averaged 20 on the hwy according to the dash

tuned by jay greene
 
Last edited:

DoubleB223

Junior Member
Joined
May 13, 2017
Posts
26
Reaction score
10
Location
Ky
Ram Year
2017 QC
Engine
Hemi 5.7
I need to get a custom tune, all I have is the can tunes that come on the diablosport intune i2. So I could be talking out of my ass. But I just put the stock tune back on and was getting better MPG. So idk!


Sent from my iPhone using Tapatalk
 

00buck

Junior Member
Joined
May 13, 2017
Posts
5
Reaction score
2
Ram Year
2016
Engine
5.7
My wife drive a 2016 5.7 Laramie Longhorn and we never see a message about it slipping into "Eco" or MDS mode.

Is there a chance it isn't turned on on her truck or does a message not apply?

I can feel something "change" when going over an overpass, but it doesn't feel like it's downshifting.
Thx


Sent from my iPad using Tapatalk
 

Cmsharp

Senior Member
Joined
Dec 2, 2016
Posts
388
Reaction score
156
Location
Rogers, AR
Ram Year
2016
Engine
5.7 Hemi
You have to check your settings and turn on the notification to see when your going into eco mode.
 
Top