Hello all I hope this is in the right section of the forum. We are currently on a day out and after driving 50 miles out of London, the temp gauge still is showing the car is cold. When we get to lights, the temp increases and the needle is just below 80. When I drive again it goes down to the marker below 80, this marker has not label. The gauge definitely works but from my experience of w123s, once warm the temp does not move. This is my first MB with aircon and its been on all the time. So my question is, what is the correct operating temperature of my E200 (estate)? It's a 1994 with 119k miles. Ps. Could it be the thermostat is not working. I've also found it to be pretty uneconomical, a fill tank with city driving yielded 260 miles with very careful driving in E mode on the box. Tyre pressure is excellent, nitrogen filled. Many thanks.