Okay...this is a weird one. I bought a bluetooth OBDII scan unit that works with an app on a phone. I set it up correctly and everything works fine...the speedo and tacho are true to the dials in the dash, etc. BUT the temperature gauge climbs to just below half way and stays there (regardless of engine load, etc...) whereas the OBD unit shows the temperature climbing to 81% (still out of the red danger zone but I tested this on a cold Melbourne day so I was a bit alarmed). I don't get it... the dash gauge says one thing and the OBDII says something else. I have been told that there may be more than one temperature sensor involved in the engine and that manufacturers keep the temp gauge "dumb" (not overly reactive to engine temperature fluctuations) to stop people freaking out when the gauge climbs when they are belting down a freeway or up a hill. Me...I don't know what to think. Are there any tech gurus out there who can advise please? The car is a VF Evoke with the 3L engine. Only done 55,000 km thus far. It is driven sedately, regularly serviced...etc...etc... In fact I have the services done more frequently (and have the synthetic oil changed) to prevent the dreaded timing chain stretch. I treat my cars like gold.