MDS not working (I know, most of you don't like MDS)

[SpeedyV]

IDK about your 2020, but my 2019 is a tomb. It’s one of the quietest vehicles I’ve owned.

Ditto on that. I hear a little wind noise at 75 mph, but changing the background music volume from 7 to 8 is enough to compensate!

 

[Granite2WD]

A lot of debate here, but little to answer your question; so I'll try. First, MDS will kick in more frequently once you get more miles on your truck. I started to see MDS kick in more often after about 6,000 miles. Gas mileage will also improve as the truck "breaks in". Second, the MDS "on/off" cycle is super sensitive to throttle input. If you are one who is a little heavy on the throttle; then expect that your MDS will not be active often. You must maintain a steady speed and a light foot; if you have a tendency to speed up and slow down a lot then MDS will be off more than on. If you wish to keep MDS engaged; then do slow and minimal adjustments to your gas pedal. Third, MDS is also sensitive to RPMs; so eventually you will get to a speed/RPM where MDS will not engage; for me, that is between 72 and 75 MPH (above 2,000 RPM) depending on the grade of the roads.
I have had my truck for about two years now and have programmed myself and my driving habits to keep MDS engaged. Aside from stopping a light or two; I can keep MDS engaged on my entire 15 mile ride to and from work averaging between 45 and 65 MPH.

To maximize your MPG you need:
1. Accelerate to speed swiftly rather than slowly getting up to speed.
2. Lightly feather the gas pedal to get to your desired holding speed.
3. Have your ECO light turned on and when ECO engages try to hold your pedal steady making only slow, light, and very gradual changes to the pedal to maintain your speed.
4. Drive under 75 MPH and/or 2,000 RPM.

Wind is also a factor that will affect MDS.

I've heard people say this "Accelerate to speed swiftly rather than slowly getting up to speed" before and I've never understood it. Why would accelerating faster save gas? When I accelerate slowly, I'm in MDS most of the time. Seems backwards to me.

 

[Scram1500]

I've heard people say this "Accelerate to speed swiftly rather than slowly getting up to speed" before and I've never understood it. Why would accelerating faster save gas? When I accelerate slowly, I'm in MDS most of the time. Seems backwards to me.

The theory is the more time you spend accelerating, the more gas is wasted. Now you don't need to light tires at every take off, but there is a sweet spot in the middle. It's better to get up to 60 mph in 15 seconds at 10 mpg rather than 20 seconds at 12 mpg

 

[Willwork4truck]

And as far as the drivers behind you, they seem to be happier if you don’t accelerate slowly, especially on ramps. I’ve been bad about that in times past and thats usually when I get the “RAM is #1” gestures.

 

[Granite2WD]

The theory is the more time you spend accelerating, the more gas is wasted. Now you don't need to light tires at every take off, but there is a sweet spot in the middle. It's better to get up 60 mph in 15 seconds at 10 mpg rather than 20 seconds at 12 mpg

Here's an article that supports your idea; https://www.popularmechanics.com/cars/a6827/6-driving-tactics-to-save-gas-this-weekend/

 

[Richard320]

I've heard people say this "Accelerate to speed swiftly rather than slowly getting up to speed" before and I've never understood it. Why would accelerating faster save gas? When I accelerate slowly, I'm in MDS most of the time. Seems backwards to me.

I watch the instant mpg when I drive. It seems that whether I accelerate briskly or ooze up to speed, it shows like 7 mpg. So do I want to get 7 mpg for an eighth of a mile or for half a mile? Get the gas-sucking mode over! Then once it's up to speed, inertia tends to keep it rolling along with minimal throttle. Note I wrote briskly and not floorboarded.

 

[Billy James]

I've heard people say this "Accelerate to speed swiftly rather than slowly getting up to speed" before and I've never understood it. Why would accelerating faster save gas? When I accelerate slowly, I'm in MDS most of the time. Seems backwards to me.

Because of the time that slow acceleration takes vs swift acceleration. You are dumping gas for a longer period of while trying to get the mass of the truck up to speed at an RPM that does not maximize the efficiency of the engine. It does make a difference.