[Eljaro]

I do run a thermostat with Evans. It is one with a larger opening than normal . The Evans stuff is rather soupy and a bigger central hole helps.. Using no thermostat will delay the warming up, especially in colder regions. No problem down south with warmer weather.

I have had some friends older cars, like Jaguar XK140, with overheating problems, which makes the cooling fluid to overflow and cause a big mess and alarm. With Evans temp runs up and over the water boiling point temp but nothing happens, just keeps son running.
Remember that the temp at the head/block junction is far over boiling point of water. All you need there is for the heat to be drawn away, and that is done better by Evans at 220ºF than by water at 205ºF with some air bubbles going with it. Air and gas expand with heat, which is what causes stress on the cooling hoses and spilling over of cooling fluid.