VS,

As soon as you touch the throttle at any speed, the stock TCM immediately unlocks the TC and depending on speed and how deep you get into it, may shift the trans down one or even two gears. This instant rise in revs and "slippage" of the TC gives you the feeling of "peppiness", but is very wasteful of the motor's energy. If you had a manual gearbox, this would be like always instantly downshifting when you just crack the throttle open a tiny bit, regardless of whether you require strong acceleration or not at that particular moment. Diesels are particularly rpm sensitive in terms of fuel consumption. You want to keep the revs as low as possible and use the diesel torque so you minimize fuel consumption.

The stock TCM does not allow you to do this. GDE's TCM does. When you apply moderate throttle with the GDE TCM, the TC remains locked and the trans does NOT downshift. This saves fuel. If you want max acceleration, the latest version of the GDE TCM requires that you apply more than 3/4 throttle to unlock the TC and trigger a downshift, or you can manually downshift, or if you are in 4rth or 5th gear, you can hit the "OD Off" button on the side of the shifter. It's all very easy if you think and act the way you would if you had a manual trans. The TCM has not affected your power output. If you floor it now, your Jeep will accelerate just as fast with the GDE TCM as it used to. It just gives you options you didn't have without it.

If you miss the "peppy" feeling, go back to the OEM TCM. The price will just be about 3 MPG.

(When I first installed the prototype GDE TCM, my wife told me it felt like her Jeep had a "restrictor plate".)

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

Doc,

Thank you that explained a lot. I will be keeping it no matter what if the 3 mpg is true and like you said just manually down shift it if needed.

You will see as much as a 4 mpg gain if you exclusively drive between 35 and 55 mph. Mostly 65 and up yields 1-2. 50/50 highway/secondary usually yields a 3 mpg gain.

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP