What is MDS Multiple Displacement System How to Disable MDS Temporarily

Okay, friends. So I bought this Ram 1500 specifically for the 5.7 Hemi power. We all know it and we all love it. One thing I noticed though when I'm driving it, is it definitely feels as though something's going on within the engine that's kind of bothersome to me. I like to have the full Hemi power all the time. There's something going on in there that I wanna talk about. It changes things a little bit. Let's get into it.

MDS essentially stands for Multiple Displacement System. So essentially what it's gonna go ahead and do is turn off four of your eight cylinders. You have a V8 engine, which of course is gonna have a lot of power and use a lot of gas. The way that it's gonna do that is to turn off four of the injectors and then it's also got some solenoids that are located inside the engine that are gonna collapse the valves for the intake and the exhaust. And this is of course, gonna help with fuel economy and reduce the amount of emissions getting pushed out into the atmosphere.

Now, some people will tell you by pushing on your tow/haul button on your Ram 1500, that's gonna deactivate your engine's MDS system. Well, that's kind of true and it's kind of false. For the six-cylinder transmissions, you will notice that it does actually deactivate the MDS system. Unfortunately on the eight cylinders, it doesn't do that. Essentially, all it's really gonna do for that is just kind of change your shift patterns for your transmission. Now we should have probably mentioned that there's gonna be a difference between the six-speed and the eight-speed transmissions. What you're probably gonna notice is for the six speeds, you might have a shifter that looks a lot like this, and essentially you can just come on down here like this, and then you can just go ahead and go to the left, which is essentially gonna put it into manual shift mode. And then just go ahead and shift this all the way over until you come up to sixth gear for the six-speed.

Now, other trucks, what you might happen to notice is you don't have a shifter like this. Some of the trucks are gonna have a little knob right here that's gonna go park, reverse, neutral, drive, and so on. If that's the case, you're gonna come right over here to your steering wheel, and you're gonna find your little shift buttons here. Mine doesn't have it because my shift linkage is down lower. Essentially, just go ahead and push that little negative button or down button, and essentially that's gonna put it into shift mode. The next thing you wanna do is continue by pressing up until you get to the maximum amount of gears that your truck has, if it's a six or an eight. And if you have a column shifter up here, you're essentially gonna have those same buttons up here and it's the same thing. Just press the negative while you're in drive. It's gonna put it into shift for you and then just go ahead and press positive until you get up to your maximum shift range.

So now by having your gauge cluster set, so you have the maximum amount of gears used while you're driving, you can continue driving. And what you're gonna notice is your MDS system is not gonna be kicking on. So essentially, you're gonna be staying in all eight cylinders all the time for maximum horsepower and torque. Something that I wanted to mention real quick before somebody leaves it in the comments section, the MDS and the eco light aren't necessarily part of the same system. You might happen to notice that it seems as though they both kind of activate/deactivate at approximately the same times, but it's two complete separate units/systems of your vehicle.

So now we have our automotive scanner hooked up to it so you can see that the MDS is actually activating and deactivating. So right now I can tell just by listening to the engine, it's activated. I'm gonna give it a little bit more gas, and you can see that it deactivates. We're going up a hill right now. So once we get over the top of this hill and we get some nice flat surface, I'll show you it'll come back on again.

Now I'm just gonna go ahead and push that tow/haul button. And as you can tell, it deactivates. I'm gonna go ahead and push it so it's off now.

Now we're cruising on four cylinders again. So now I'm just gonna go ahead and use my shifter. I'm gonna drop it down one gear here, and then I'm gonna put it into my maximum range, which for me is six like I said. And what we're gonna notice is that the MDS does not kick on. I can cruise along all day like this, no MDS, full power. A good reason why you might wanna have MDS system inside a truck like this is essentially for when you're cruising down the highway and you're not necessarily using so much throttle, you're just overall cruising. This is gonna help make it so you're the most fuel-efficient as possible.

Okay, so now that's a quick, easy way of temporarily disabling your truck's MDS system. If of course you want to do it permanently, you can go out and buy yourself a tuner. Otherwise, just take a couple of extra seconds, set it like this, and you should be good to go. I hope you liked the video. I hope you learned a little something. If you did, and you wanna talk about it, leave it in the comments section below because I always love to hear from you. If you like the video, smash on the like button for me. It would mean the world. While you're at it, go ahead and subscribe and ring the bell. That way there, you can be kept up with all of our latest content. Thanks.