The aim of emissions minimising could well be the reason. When the coolant leak/rad problems were happening I think a solution was a flash of the ecu. It changed the triggering of the thermostat to reduce pressure build up from cold starts. I think it reduced the ‘stat opening temp thus allowing coolant to circulate earlier and at a lower temp. That would slow down coolant warming up. Basically similar to changing mechanical thermostats to different opening/closing ranges. Even removing the stat completely!
I’ve only had my Plus Four a short time so this winter will be the first heater test in earnest. I assume as it is MY23 model it should have the latest thermostat settings. Heater tests so far show good output and control. Heated seats work well too. Bum cooking on hotter setting in fact!
