You've got great timing...
Did a quick test just a little bit ago. Current ambient temperature is 28-29F.
Drove my A3 Jetta with whatever thermostat it has in it with non Evans coolant in it. Starting from cold, Scanguage stated coolant temperature at 30F. Drove my son to school a seven mile one way trip that has two five stop signs very early on followed by a run to school at 55MPH, then slowing down into town. My temperature at school was about 177F over that seven mile stretch. Total round trip distance was 14 miles
The route back starts with three stop signs, then the run back home at 55MPH into town where I have two stop signs to deal with. My temperature at home was about 188F.
In contrast, my Jetta A4 with the hybrid tstat, Evans NPG+, and the overall OEM gearing allowing the RPMs to be lower at the same speed, my starting cold temperature was 28F. At school arrival (no child for the drop off, but I did do a courtesy stop for research...LOL!), the Scangauge temperature was around 166F. At my arrival at home, my temperature was 200F.
The reason for my test was that it I'm mentally struggling with "how" my A4 warms up. Over the same distance, I eventually achieve a higher temperature, as expected (assuming that my A3 has a thermostat of 187 to 192F). But I'm struggling with the warm up at my half way point: I think that my A4 should similarly warm as my A3 on the first part of this route. One part of me is thinking that this is the result of the Evans coolant, and another part of me is questioning my assembly of the thermostat.
I will fill up tonight as I'll have about 330 miles on this first tank following the change of the thermostat that was in my A4 and the change to Evans coolant.
I could change the coolant in the A3 and do another back to back drive of both cars to control for ambient temperature, and that might be the easiest way to come up with some answers.