Poll- Do you like MDS?

Do you like MDS?


  • Total voters
    326

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Octane

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The only thing to like more than MDS is 20 weight oil… oh and maybe the oil filter location.
I agree...but I've actually seen worse filter locations.I had a truck once before that had a bad filter location but was easy to change spark plugs.Traded it for a truck that was hard to change plugs but had a better filter location. I cant win.lol
 

JF19Longhorn

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South Jersey
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2019
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5.7 ETorque
I drive mostly highway (65mph+) so it is almost entirely useless for me as it will not engage on my truck at those speeds unless I have a hell of a tailwind and am going downhill. In fact, on my truck, it rarely engages above 45mph, even on perfectly level ground.. now when it does engage I do notice the instant mpg jumping well into the high 20's.. but those times are such a small % of my driving that I doubt it makes much of a difference in the long run.
 

Tim7139

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2020 Classic ST Crew 4x4
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5.7 Hemi w/8 speed 3.92 gears
i had to change my vote. originally i said i just didnt prefer it. now that i have had the truck for a month, i hate mds. the lag time sucks and with a loud muffler the sound is horrible.
Glad my butt dyno is not sensitive enough to measure the up to 4 millisecond activation time. Stock SSV mufler sounded fine, but the ST dual mufflers sound even worse whe it kicks in.
 

JJPMustang

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2014
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I didn’t read all 25 pages but MDS has kept my single exhaust stock. These trucks sound TERRIBLE with anything but OEM when MDS engages, IMO.

So what would be a cheap swap for a Magnaflow or similar turns into having to play games with the manual mode every single time or driving around in tow/haul hitting the button every time. Or paying for a tuner… all to maybe save 1 mpg for the EPA test? No thanks!
 

TotallyHucked

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Didn't read through the whole thing but that blew my mind when I read that it doubles the injector PW on the other 4 cylinders when it goes into ECO, that literally negates any benefit. I've only had my truck for 2.5 weeks now and been testing. First 2 tanks were MDS activated, this tank is with it turned off to see if there's a difference. If not, it'll get turned off by my tuner buddy soon and I'll throw a muffler on it. I wouldn't doubt a bit if the heat differences contribute to the manifold issues as well.
 

Docwagon1776

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Didn't read through the whole thing but that blew my mind when I read that it doubles the injector PW on the other 4 cylinders when it goes into ECO, that literally negates any benefit.

It doesn't double it, although it does drastically increase it. The benefit is relatively minor and probably not something you'll notice in a couple of tanks vs all the other variables. Headwinds make more of a difference, for example.

The easiest way to understand how it increases efficiency is its like a spring made of air in the deactivated cylinders. Instead of using the energy to shove the exhaust air out and draw the intake air in, it uses that energy to compress the air and then get that "spring" to expand and give a little shove to the piston on it's way back down.

Reducing pumping losses isn't going to net you a huge gain, how much depends on driving style, but it's *a* gain.
 

MRFREEZE57

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pacific northwest
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2016
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5.7 hemi
It doesn't double it, although it does drastically increase it. The benefit is relatively minor and probably not something you'll notice in a couple of tanks vs all the other variables. Headwinds make more of a difference, for example.

The easiest way to understand how it increases efficiency is its like a spring made of air in the deactivated cylinders. Instead of using the energy to shove the exhaust air out and draw the intake air in, it uses that energy to compress the air and then get that "spring" to expand and give a little shove to the piston on it's way back down.

Reducing pumping losses isn't going to net you a huge gain, how much depends on driving style, but it's *a* gain.

That is why I deactivate mine every time driving the truck, checked with a local indy shop was quoted $1000.00 to permanently disable as they have to buy some code from Chrysler.
 
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