I have a 2006 A3 2.0 TFSI which I bought just over a week ago. What is the normal engine temperature? Mine is staying at about 75C and is pretty quick to get up to that temperature. My old A4 with the same engine used to stay constantly at 90C. I left the car idling for a while and the temperature did not change but the radiator fans were turning slowly. I know that the radiator is kept at a cooler temperature with the aircon on so I switched it of and the temperature went up to 90C. I took the car for a drive along a dual carriageway and the temperature stayed at 90C. On the way back I switched the aircon back on and it went down to 75C. Is this normal or is the thermostat faulty and opening slightly at 75C?