All thermostats open at the given temp it is rated for. But is not full open until 15deg later. So a 180 opens at 180 but is not fully open till it hits 195.
There are many other factors when it comes to temps in the motor. Main one is ambient air temps. A motor will run cooler on a 70 deg day then on a 100 deg day.
So judging temps cannot be done just by the t-stat.