Turning off MDS kills my gas mileage..

[Kotta390]

What exactly do these shutters do?

From my understanding they shut off incoming air to the radiator and help direct air around the truck instead of through it. It only utilizes this feature when more than enough air is being used to cool the radiator.

 

[KahneFan]

They close at a certain speed to help aerodynamics. Here's a video...

https://www.youtube.com/watch?v=AQjalNl-ias

It's on an EOD, but gas engines do the same.

And Google's description...

Active grille shutters are popping up on a number of new models, including the 2015 Ford Mustang. The shutters open and close automatically to control airflow, reducing aerodynamic drag and improving fuel efficiency.

 

[SlowRoller]

Also help w/quicker warm ups in cold temps, but main purpose is aero's

 

[LABIGHORN]

I've had my 2010 Ram Bighorn for 4 years now and I have hand calculated the milage ounce. I was satisfied with it. I drive roughly 50000km a year and just this past spring I turned my Mds off with my programmer running 87 tune on 89 fuel. I don't notice to much difference if the gauge goes down I fill it up. It is a much nicer truck to drive in my opinion. No hunting in and out of MDS like it did around here with our hills. I'm still satisfied with my mpg, it's a truck pushing well over 350hp I'm not expecting Prius like milage and I don't get Prius like performance.

Sent from my SM-G870W using Tapatalk

 

[BlownGP]

Just put the transmission in manual mode (8th gear), it will shift the same but MDS will not kick in.

If you have a tuner you can disable it permanently

What's strange about that now that I've driven with MDS turned off is. Putting into manual mod sounds way different than driving with MDS or MDS off.

When I put it in tow/haul or manual mods. It feels like a totally different truck.

 

[SilverStreak88]

What's strange about that now that I've driven with MDS turned off is. Putting into manual mod sounds way different than driving with MDS or MDS off.

When I put it in tow/haul or manual mods. It feels like a totally different truck.

It turns into "beast mode"

 

[bassheadhemi]

What's strange about that now that I've driven with MDS turned off is. Putting into manual mod sounds way different than driving with MDS or MDS off.

When I put it in tow/haul or manual mods. It feels like a totally different truck.

Yeah you're right, just did some test and noticed some difference when braking where it downshift more aggressively similar when I'm in tow mode.

I remember reading somewhere there's like 50+ possible shift pattern depending on different condition so I'm not surprise. This probably means that it will take some times before we see real tuning for the 8HP tranny due their complexity. But again the 8HP is used in BMW,Audi... so I wouldn't be surprise to see something coming from that side first.

 

[SilverStreak88]

Just curious, but on the 4th Gen's, do ya'll have a button to cycle MDS on and off? On my truck the only way to turn it off without a tuner is switching to Tow/Haul mode.

 

[Kotta390]

Just curious, but on the 4th Gen's, do ya'll have a button to cycle MDS on and off? On my truck the only way to turn it off without a tuner is switching to Tow/Haul mode.

On the 3rd Gen Rams, there is no way to turn off MDS that I am aware of except with a tuner.

 

[SilverStreak88]

On the 3rd Gen Rams, there is no way to turn off MDS that I am aware of except with a tuner.

You are able to disable it when you put it into Tow/Haul, I have it turned off with my SC.

 

[Kotta390]

You are able to disable it when you put it into Tow/Haul, I have it turned off with my SC.

I don't remember on my 2006 if MDS was active in tow/haul mode, but it would make sense. Although you do lose your second overdrive capability.

 

[SilverStreak88]

I don't remember on my 2006 if MDS was active in tow/haul mode, but it would make sense. Although you do lose your second overdrive capability.

Yes, it shifts quite different.