so I recently purchased a 2017 Mercedes Benz CLA 250 its still under warranty . However the hot/cold gauge is really throwing me off. I got a full inspection and it needed coolant and I noticed when driving the car the gauge seems to be high, I was able to get the thermostat replaced and its doing the same thing, is this normal? i talked to a few mechanics and they said that's just how Mercedes thermostat run a little higher, please advise