Mine sits there at about 50mph, but at idle in traffic it can go up to 225, the 2nd last point. I replaced my thermostat with an OE mazda 2 stage thermostat, 198/195F.
It seems to hold pretty well when it's cold out, so I'm going to try to flush it out again and see if I can't clear out all the orange junk that got left when some idiot put sealant in it.