I too have been using the ScanGauge for a number of years. Besides the more common parameters, the X-Gauge function may allow you to add other functions. In my case, I wanted to monitor my transmission temperature. On the road with my trailer, I usually monitor that, along with torque converter slippage (indicating whether the torque converter is locked or not), and gear ratio (indicating what gear is being used, along with MPG to try to maximize my fuel mileage. The ScanGauge will monitor 4 functions at a time, but each function can be easily changed to something else with a few button pushes.
You can also view mileage and other parameters for the current trip, day, previous day, and since the last fill-up (tank). Some of those parameters are fuel mileage, gallons used, gallons to empty, miles traveled, max temperature, and max rpms.
You can also adjust the ScanGauge MPG to show closely what your actual mileage is. I do a spreadsheet over a number of fills to make sure I I get it close to actual, then adjust about once a year.
You might want to call ScanGauge to make sure it is fully compatable with the MBS platform.
Did I mention that it will read error codes, and turn off the "need engine service" light ?? The battery in my truck went dead a while back, and when getting it started back up, the engine light came on. I checked the code, indicating a computer power loss. Figuring the dead battery caused the code error, I reset the engine service light, and all has been good since. Taking the truck to a shop would have probably cost me $80 or so.