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  1. #1

    Default I disabled AFM as an experiment.

    I used my Hypertech to disable AFM on my truck as an experiment. SO many folks are constantly talking about oil consumption, AFM makes for WORSE MPGs, etc., that I thought I would give it a try.

    With AFM I get between 17.8-18.3 MPG Monday through Friday back and forth to work.

    I disabled AFM last night and topped off the tank this morning for the drive.

    I got 20.1 MPG driving to work, which is surprisingly slightly better than what I get with AFM on. Now I know weather, fuel blends, etc., have an impact on fuel economy as well, my driving back and forth to work at least takes the terrain out of the equation.

    I will keep the forum posted.

    At the very least, I don't have to hear the AFM turn on and off and hear it on my exhaust.

    2013 Silverado LTZ White Diamond Crew Cab

    Advent OGM1 Navigation
    Husky Liners GearBox Underseat Storage
    Airaid MIT
    EGR Rail Caps
    K&N Air Filter
    Flowsound 40 Muffler
    Hypertech Max Energy Tune (only top end limiter removed and AFM disabled)
    Chrome Tailgate Handle Cover
    TonnoPro HF-155 Tonneau Cover
    WeatherTech Front and Rear Splash Guards
    Husky Liners X-Act Contour Floor Liners
    WeatherTech Side Window Deflectors

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  3. #2


    So were we right?

    2009 Chevrolet Silverado 1500 LT Z71 Crew Cab "All-Star Edition"

    Line-X'd Bed
    Line-X'd Custom Brush Guard(Heavy Duty)
    5.3L Flex Fuel
    275/65R18 Toyo Open Country AT2's
    2" Rough Country Leveling Kit(want to get the 2.5 RC kit)
    EGR In-Channel Vent Visors
    Exterior PLUS Package
    Interior PLUS Package
    K&N Drop-In Air Filter
    Cat-Back Dual Exhaust
    Black Bowties
    Diablo Sport Predator(AFM Disabled)
    Towing Mirrors
    Next Planned Mods
    Blacked out Tail Lights
    Aftermarket Rims

  4. #3


    Quote Originally Posted by ChevyBoy2009 View Post
    So were we right?
    I'm not going to declare anything after only 25 miles. So far it looks promising.

  5. #4


    something to bear in mind is the fact that the ECM relearns things as you drive, so as you get more miles on it should only get better.

    at least for me, the sweet spot if running 60-65 with the cruise on. flat ground the truck returns 23 on the instant econ display, and lots of interstate driving seems to support that.


    2011 GMC Sierra SLE 5.3 Z71 4X4 Stealth Gray Metallic / 2004 Chevy Impala LS 3.8 Cappuccino

    Tow mirrors - Diablew Tuned - Flowmaster Regular 40 - Ready Lift 2.5' lift - BFG LT A/T K/Os - Carr Light Wing - TruckLite LED lights - Optima Red Top - 50% Front Window Tint - Line-X bedliner - Airaid MIT - Tekonsha P2 - ARS Billet Grill - Fia custom fit seat covers

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  7. #5


    The absolute best I ever got on my route to work for the week was 18.8MPG. Not bad for a heavy truck, but if it can do better with disabling AFM, then I'll do it.

  8. #6


    I cant wait to get my Diablo and see what kind of numbers my truck will get

  9. #7


    You should chart it. Do a daily log and include the total miles, the MPG shown, weather conditions, etc.

    10 Chevy Traverse LT AWD
    02 Chevy Trailblazer LS (110K+ miles - loaded except for 4WD - WRECKED!)
    99 Chevy Cavalier LS (105K+ miles - commuter car)
    78 Chevy Suburban Silverado (454, 3/4 ton)
    62 GMC 3/4 ton Pickup (350 police interceptor)

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  10. #8


    For the most accurate results, go through several whole tanks with AFM off and then get back to us. Good luck with the experiment!
    Clint (TX) 2001 Silverado LS 4.8L auto 2wd ECSB [GARAGE]
    Gasoline or gunpowder: If you ain't burning one, you ain't having fun!
    NRA Endowment Member 5 24 48 88 - Hendrick Motorsports FTW!

  11. #9

    mfleetwood's Avatar
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    Jul 2010
    Denver, CO
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    Good thread topic...thanks for starting it!

    Mike (Denver, CO) - 2008 Sierra 1500 Z71 SLE 5.3L 4WD

    SUSPENSION: Rancho 4" Suspension Lift; Rancho RS9000XL Shocks; Rancho Skid Plates; Rancho MyRide Wireless Shock Controller;
    BFG All Terrain KO 315/70/17
    DRIVE TRAIN: 4.56 Gears; Detroit TrueTrac Differential; True Cool 40k Transmission Cooler
    PERFORMANCE: DiableSport Predator Tuner; Custom Tuned by Diablew; Magnaflow Exhaust; AFE Cold Air Intake
    ELECTRONICS: Kenwood DNX6180 Touchscreen; Subthump box w/10" Kicker; Driver Information Center (DIC); Rear View Camera
    ACCESSORIES: Westin Brush/Grill Gaurd; Westin Nerf Bars; Truxedo Tonneau; 20% Tint; Tow Mirrors w/Heat & Signals

  12. #10


    Update, day 2.

    I arrived at work with the DIC reporting AVG MPG of 19.1. I will report back tomorrow.

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