The VMS systems are electronic engine monitoring and display systems. Think of it as a digital dash that can display any parameter the engine and transmission measure. The electronics in our engines and transmissions monitor and store dozens of pieces of data which unfortunately aren't presented to us as drivers. There is quite a bit of data that the engine collects that I'm interested in when driving but I don't have a gauge for. The VMS simply records and displays that data.
As a partial list from my owners manual the system will display the following; Accelerator position, Battery voltage, Cruise control set speed, Coolant temperature, Engine load, Fuel rate, Horsepower output, Instantaneous MPG, Intake manifold temperature, Power factor, Rolling MPG, Speed, Tachometer, Torque converter status, Torque output, Transmission temperature, Transmission mode, Turbo boost pressure, Oil pressure, Fuel injection pressure and a bunch more.
In addition to monitoring, the system also detects and reads out fault codes which would normally just set a check engine light. Having a display of the detected failure while logging other data that occured which triggered the defect can be valuable. I'm really anxious to try the system out on a trip we're planning this week where we'll be climbing some steep hills in West Virginia. It will be interesting to monitor the engine, transmission, and turbo temperatures while watching boost pressure and torque output of the engine while climbing. Of course, not as important, but still interesting would be watching fuel delivery flow and average MPG fluctuate with the amount of boost supplied to the engine. Toys for boys I suppose
I haven't had a chance to use the system yet on a trip, but there are a whole group of trip related features also available such as monitoring fuel usage, average speed, running time, average MPG, estimated fuel required, ETA, etc.
After we get back from our trip, I'll post again how the system has performed.