Electric fan won't cool at highway speeds

Someone else already asked this, but I will again,

What is wrong with 180°-210°?

There is nothing to worry about. And a 160° thermostat will not make it run cooler. That will just make it warm up slower. Once you hit 160° it's open and still open at 180°, just like a 180° thermostat is open at 180°.

AIRFLOW PROBLEM, like stated above !