Adjusting the MPG Reading on a GT Tuner to Read Accurately

Modified on Tue, 6 Sep, 2022 at 1:28 PM


First, you need to figure out what percentage the MPG reading is off by. 

1. Figure out the percentage using this formula: GT average economy minus calculated economy divided by the calculated economy. 

2. On the tuner go to Main Menu->Vehicle set up/settings->Adjust economy display. 

3. Increase, or decrease by whatever percentage you are off by.  

*Increase the percentage if the GT is reading lower mileage than you are getting. Decrease the percentage (go negative) if the GT is showing higher mileage than you are getting.