I am in florida, the outside temperature is 92 degree F. the problem is that when I stop at the red night or waiting for about five minutes with the air-condition on only, the temperature gauge is rising higher, and going toward red zone, but when I increase the speed and not waiting or slowing down idling around 700 rpm, the temperature is normal all the time, so that I know you mention that we should use bmw coolant becasue of some high tech ingredient which i did not it yet, what do think of any issue related to this matter, thank you