Bully Dog 40420 gauge GT tuner - Manual (Page 15)

GT
DIESEL
14
Driving Coach Setup (continued)
Checking Average Fuel Economy
It is important to check the accuracy of the average economy readout on the GT at least once every changing season. There are many reasons to check
and adjust the average fuel economy, here is one example: The fuel delivered to gas stations during the winter contains an average of 1.3% less energy
than the fuel delivered in warmer seasons. That means that the same amount of liquid is going into the tank, but it is 1.3% less effective, on average.
There are many similar factors that affect your fuel efficiency that you cannot control and the GT cannot sense or adjust for. That is why it is important to
adjust the fuel economy of the GT every once in a while.
To adjust the Average Fuel Economy displayed by the GT, follow these steps:
1. Go to the gas station and get a full tank of gas.
2. Reset both of the following gauges before driving away from the gas station:
- The Average Economy on your GT.
- The trip odometer on your vehicle.
4. Drive the vehicle for an entire tank (or two)
5. Calculate your vehicle’s average fuel economy by hand using the following equation:
6. Use the equation below to calculate the Percent Difference between the average fuel economy that you have calculated and the aver-
age fuel economy that is displayed by your GT.
Adjust the Average Fuel Economy
Follow the steps listed below to change the average fuel economy that is displayed by the GT:
1. Go to the Main Menu
2. Choose Vehicle Setup
3. Choose Adjust Economy Display
4. Use the buttons on the right to move up and down the percentages
5. Choose a percent value that is the opposite sign of the Percent Difference that you calculated using the equation above.
- For example, if you determine that the Percent Difference is 14%, you should choose -14%.
• NOTE: If the speedometer on the vehicle is not accurate,
then the odometer will also be incorrect. You will need
to be able to calculate the exact number of miles driven
before your next refill.
GT Average Economy - Calculated Average Economy
Calculated Average Economy
Example 1: Assume the GT Average Economy is 24 mpg and the Calculated Economy is 21.
24-21
21
3
21
Step 3. Percent difference = .142 or 14.2% round down to 14%
Percent difference =
Step 1. Percent difference =
Step 2. Percent difference =