[skyking]

Not at all. One of the things about a truck like mine is huge excess cooling capacity.
It was designed for a worst case scenario of making a continuous 180 HP while towing a 9300 pound load up a steep grade at high altitude on a hot summer day.
Real world loadings are paltry, by comparison. I ran it all last winter with NO cooling fan, for example. Then I started blocking the grille off to see what heated up. I have instruments for transmission temps, EGT, intake temps, you name it.
Now I have a couple of electrics that I run on low speed when towing the 5th wheel.
Last week I took it up to 5000 feet on a cool day on Rainier, towing an empty 3500 pound flatbed trailer with the fans turned off.