We set up the scan gauge to read the following parameters.
1. TPS: When using cruise control the Throttle position will indicate when the transmission will shift down on a hill. I can tape the brake and hold it in over drive longer by allow some speed to drop slightly while going up the hills.
2. FIA: Fresh air intake will give us an idea of the outside temperature. When traveling on the highway it is about 2 degrees cooler that the intake temperature
3. MPG: Use this to adjust driving to current conditions to get the best fuel economy.
4. Ave MPG: To get an idea of our overall economy or lack of. Interesting to see how terrain, road conditions, and weather impact overall economy.
We use the GPS for MPH info and it shows the legal limit...keeps me out of trouble ;-).
Plan to program in trans temp but haven't done it yet. So far have not felt the need to monitor it, but there are trips where that info would be very useful.