Computer MPG reading incorrect

Chuck84

Caught the Bug
I have a 2009 JKU with a newly installed Motech swap. My computer is telling me that I am getting 22 mpg when it is actually closer to 16 mpg. Does anyone have an idea of how to fix it? I have been told there is an adjustment up above the original Jeep pedal(yes, the pedal itself is gone). I have done multiple internet searches and I can not find anything about this adjustment. Hoping someone might be able to give me some insight.
 
I have a 2009 JKU with a newly installed Motech swap. My computer is telling me that I am getting 22 mpg when it is actually closer to 16 mpg. Does anyone have an idea of how to fix it? I have been told there is an adjustment up above the original Jeep pedal(yes, the pedal itself is gone). I have done multiple internet searches and I can not find anything about this adjustment. Hoping someone might be able to give me some insight.
Maybe a dumb question, but did you reset the computer to your current diff gears and tire diameter?
 
There is a new computer for the engine as well as the transmission, but since the Jeep computer is still there I never thought to look at it.
 
If you have the Aero Force Gaige there’s a way to program it for MPG uses the GM computer. I’ve never tried.
I have hand calculated mine and got 21MPG but I was behaving myself.
 
The motech kit comes with a small wedge that goes on the old jeep gas pedal. The old gas pedal is cut off but the sensor is still in there likely right above the new gas pedal. If you push the wedge in deeper it will lower your mpg readout. From what I understand, it's using the pedal position to decide your fuel usage and your just fudging it to a number that is close so your distance to empty reads right but it can't actually calculate your mpg correctly anymore.
 
Most definetly!
The motech kit comes with a small wedge that goes on the old jeep gas pedal. The old gas pedal is cut off but the sensor is still in there likely right above the new gas pedal. If you push the wedge in deeper it will lower your mpg readout. From what I understand, it's using the pedal position to decide your fuel usage and your just fudging it to a number that is close so your distance to empty reads right but it can't actually calculate your mpg correctly anymore.
Robbie told me about the wedge but didn't give me as much detail about it's location as you did. Getting my DTE to be a little closer to accurate is my end goal. I will try to locate it again. Thank you!
 
If you have the Aero Force Gaige there’s a way to program it for MPG uses the GM computer. I’ve never tried.
I have hand calculated mine and got 21MPG but I was behaving myself.
I am finding that it takes great effort to behave myself... I do not have an Aero Force gauge but that gives me more reason to get one. Currently using Torque Pro to monitor temps and it also offers a way to monitor trip MPG but I have not used it for that yet.
 
If you have the Aero Force Gaige there’s a way to program it for MPG uses the GM computer. I’ve never tried.
I have hand calculated mine and got 21MPG but I was behaving myself.
I am finding that it takes great effort to behave myself... I do not have an Aero Force gauge but that gives me more reason to get one. Currently using Torque Pro to monitor temps and it also offers a way to monitor trip MPG but I have not used it for that yet.
From what I've messed with the aero force gauge the MPG readout on the gm side is pretty inaccurate. Unless their is some other way to program for the fuel mileage. I am just going into the menu and selecting the MPG or Average MPG readouts. My calculated MPG floats around 15 and the readouts are giving me 19-22.
 
As stated above you can adjust the wedge and it will change the mpg calculations. The jeep pedal is still bolted in the factory spot, its located just to the right of the GM pedal. The Jeep side doesnt control the throttle anymore and does not see the throttle position, so it cant accurately calculate properly.
Using the mpg display on an AF gauge is an instant reading so it constantly changes, the issue there is that the GM side doesnt know how much fuel is in the tank, the GM side is setup to read 48% fuel so the monitors and such can set for emissions.
 
As stated above you can adjust the wedge and it will change the mpg calculations. The jeep pedal is still bolted in the factory spot, its located just to the right of the GM pedal. The Jeep side doesnt control the throttle anymore and does not see the throttle position, so it cant accurately calculate properly.
Using the mpg display on an AF gauge is an instant reading so it constantly changes, the issue there is that the GM side doesnt know how much fuel is in the tank, the GM side is setup to read 48% fuel so the monitors and such can set for emissions.
So... what I am gathering from all this information is this. I should take a road trip, hand calculate my MPG, and use a ballpark range for future road trips. Hmmm... atleast I will be smiling all the way to empty.
 
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