rvictor

Hi, I have a audi a3 1.8 tfsi petrol. Lately I have noticed that my coolant is on minimum. I have topped it up to just under maximum. I have travelled up north which was a 4 hour drive and drove back another 4 hours and my coolant was just above the minimum. Am I just getting paranoid or am I losing a bit of coolant. My temp gauge is perfect on 90 and there is ko leaksnor anything. Can someone advise further please.