I've had a ScanGauge installed on my truck for a couple of months and it's been awesome to use. Once I dialed in the correction factors for tire size and FILLUP accuracy, I've found it to be consistently accurate in calculating TANK fuel economy.

One thing that I've noticed after using the ScanGauge for coolant temp is that the coolant temp reading fluctuates under "normal" conditions quite a bit (from about 184°F to 204°F) while the coolant gauge needle on the dash doesn't move at all!

It makes me wonder if the gauge on the dash has a flat-spot in its response to indicate "normal" so people don't freak out when they see the gauge moving up and down all the time.

In "gauge" mode I usually monitor VOLTS, TEMP, MPG, and LOD (or occasionally TPS). It's neat to watch how MPG changes as LOD changes.

On my Pathy, MAP is supported so I can see how much the MAP changes at different elevations. For example, at sea level the MAP is 14.7, but on a recent trip into the mountains, it got down to about 10.5! (MAP=manifold air pressure; if the engine is off, the MAP=ambient air pressure)