ScanGauge II acts like a kill-a-watt for cars

It's a bit like a "kill-a-watt" for cars. The ScanGauge II shows you your MPG in real-time helping you learn how to drive more efficiently and improve your gas mileage and reduce costs.

The ScanGauge II plugs into most cars and provides real-time data directly from your car's engine, such as:

• Fuel Economy (MPG)
• Battery Voltage
• Coolant Temperature
• Intake Air Temperature
• Engine Speed (RPM)

It's a programmable 3-in-1 automotive trip computer, diagnostic scan tool, and up to 37 digital gauges in one.  It works on all 1996 or newer OBDII cars, including gas, diesel, propane and hybrid vehicles (though my Prius already has this information on display). It's easy to install without tools and since it's small it fits nearly anywhere.