Probably 192-195 degrees
There is usually a differential of about 2 to 3 degrees.
Trouble code P0128 means:Coolant thermostat (coolant temp below thermostat regulating temp)
Coolant Temp below thermostat regulating temp.
180 degree is stock but you could also go with 160 degree
190 Fahrenheit / 88 Celsius
Factory uses 195 degree.
Yeah it does H7 with 8k temp
check you thermostat for the temp setting
Could be, low on coolant, sticky thermostat,
195 is the thermostat that goes in a V6.
If you have an electronic Thermostat, make sure that you are changing the "Program" and not just setting the "current" temp. Most electronic ones will change the temp NOW but will change back to the program after a set amount of time.
rite temp thermostat model # 8030