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  1. #1
    Join Date
    Apr 2018
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    Active Fuel Management question

    Not sure what Dodge calls it, I know GM refers to it as AFM( where the car will reduce to 4 cylinder). My question is there a certain mph it will not do that? I just got my Daytona 392 last month and was using the cruise control today and noticed at 70mph it dropped to 4cyl, but if I increase the mph to 72 and maintain I never see it change to 4cyl. You would think if you are using cruise control it would work anytime to maximize mpg.



  2. #2
    Join Date
    Jun 2012
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    Fort Lauderdale
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    Its referred to as MDS on our vehicles. No clue as to when it cuts in and out

    Sent from my SM-G955U using Scat Pack Forums mobile app

  3. #3
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    Apr 2018
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    Thanks for the MDS..

  4. #4
    Join Date
    Jun 2012
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    Fort Lauderdale
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    Would think it has more to do with revs and throttle position than speed tho. Someone correct me if I'm wrong, but that's just how it would work the way I picture it. But I'm not going off any knowledge saying that, never looked into it that much besides deleting it

  5. #5
    Join Date
    Aug 2016
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    I’ve noticed this as well. 2017 Challenger Scat Pack.

  6. #6
    Join Date
    Jun 2012
    Location
    D/FW, Tx
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    If you remove the resonators at the rear of the exhaust you will know when it activates.Based on vehicle speed and load on engine along with engine temp. It activates such that the engine's torque and HP do not change and so is almost indiscernible. Unless you know what to feel for.
    2005 Dodge Magnum RT.
    12/2016 - Inertia big valve heads, Eagle intake, non-MDS lifters, Spartan Plus cam, Shorty headers. 390 RWHP, 390 RWTQ. (Work by Inertia)
    01/2017 - Bilstein shocks, SLP 25% underdrive pulley. s/b 400 RWHP, 400 RWTQ now. (Work by me)
    10/2017 - Replaced engine mounts with 392SRT manual transmission, added police oil cooler, additional PS and Trans coolers, Mishimoto radiator. (Work by me)
    10/2017 - Replaced Torque Converter with FTI 3,200RPM, Installed 3.06:1 Getrag kit, one piece Al DSS DS, Billy Boat 3" Exh.
    11/2017 - Wilwood brakes with 15" front brakes. (Work by me)

  7. #7
    Join Date
    Aug 2016
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    I have the mid mufflers deleted and I can feel/hear it every single time. Also, on 2015+ we get the 4 CYL displayed on fuel screen. It matches what I hear. To the OP, I agree MDS doesn’t come on near as much at 72+ mph.

  8. #8
    Join Date
    Jan 2011
    Location
    Porter Ranch, CA
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    I've had it come on even going 80mph, though not as much as when I'm cruising at 75mph. I've heard that is kicks on when torque requirements are below 80 ft. lbs. and turns off when its 120 ft. lbs. Also, I've heard you can ask your tuner to move those thresholds around if you want. I left mine stock as mine is a DD.
    2016 Charger SRT TorRed Best: ET 12.913, MPH 112.30 (DA 2446ft.), 60ft. (1.95 radials), Standing: 1.0 mile 160mph, 1.5 miles 170mph (let off to not exceed class limit of 170mph)
    AFE CAI, BBK 85mm, 180*, Diablotoona custom tune 91Oct.

    2008 Caliber SRT4 Inferno Red - SOLD [email protected] (2.327 60 ft.) MS1K v.2, MPx catted DP, K&N drop-in, NGK plugs, RT 180, Mopar hitch, new short block @ 82,000
    2007 300C SRT8 Inferno Red - SOLD [email protected] (2.003 60 ft.) AFE CAI, Predator 93 CAI, Magnaflow gutted high-flow cats, Stack intake spacer, BBK 85mm TB, JET 188, Proxes 4 275/40ZR20

  9. #9
    Join Date
    Apr 2018
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    If i get a chance today on my ride home i will toggle between my tq screen and fuel eco screen and see if it does as u say at 80& 120 ft/lbs. Thanks for the info

  10. #10
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    Apr 2018
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    Rancho Cucamonga
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    Quote Originally Posted by Mango Hemi View Post
    If i get a chance today on my ride home i will toggle between my tq screen and fuel eco screen and see if it does as u say at 80& 120 ft/lbs. Thanks for the info
    I have also read but not tested myself yet that the mds activates more often if you have a tazer with eco mode enabled.


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  11. #11
    Join Date
    Apr 2018
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    I do have a Tazer installed but I did not activate eco mode on mine.

  12. #12
    Join Date
    Apr 2018
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    Rancho Cucamonga
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    Quote Originally Posted by Mango Hemi View Post
    I do have a Tazer installed but I did not activate eco mode on mine.
    I have it enabled I just have not watched the 4 cylinder mode while I was in eco mode


    Sent from my iPhone using Tapatalk

  13. #13
    Join Date
    Jan 2016
    Location
    South Jersey
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    I mostly drive in sport mode, but in those highway trips is seen in on at around 80mph. I like it because it saves gas.


    2016 Dodge Charger Scat pack

  14. #14
    Join Date
    Apr 2018
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    I keep my dash on the fuel economy page and see it pop on all the time. I also hear it, it sounds.. Not so great. Now I'm curious about the highway cruising over 70..

    Sent from my SM-G955U using Scat Pack Forums mobile app
    2017 Pitch Black Charger Scat Pack 392
    20% tint, Billet Technologies Matte Black Catch Can, LED interior lighting, ZL1 Rock Guards, K&N drop in filter, MaxBeam Smoked LED side markers

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