Review on Advanced OBDII Speedometer KMH MPH Head Up Display with Battery Voltage, Engine Charging Voltages, Temperature & Overspeed Alarm - Perfect OBD2 Scanner for 12V Petrol Diesel Vehicles by Ken Lawson

5 stars would be excellent/perfect. It's near! Deducted 1 star just because it sometimes (rarely) doesn't start properly depending on how I turn the key on and then start (so diesel usually waits a bit). With an older Duramax (LLY) diesel engine, it is important to know the temperature of the engine (dash is located, thanks GM). This gauge allows the main/big display to show engine temp so it's perfect for what I need. It also displays the voltage, which is nice (and allows you to set the voltage offset, which is oddly necessary since the voltage at the OBDII connector can differ slightly from the voltage the battery is receiving). I'm trying the orange display because the white color is very bright at night, but I'm trying anyway. If the sensor survives, then I'll be very happy.