I have a
SGII on my F250 6.0 diesel. I watch
Air temp,
instant mpg,
boost pressure, and
horsepower.
I think I x-gauged the boost, which is just barometric pressure in psia. HP is x-gauged too, I think. Between the horsepower and boost, it helps a lot on keeping the MPG in check.
My 99 Metro with the SG1, I watch IAT, TPS, MPG and the last varies depending on what I want to watch. Mostly LOD, MAP, MPH or coolant temperature.