[Yachts]

I just returned from Creede Colorado , and during the mountain driving I un hooked the fan relay in back so it would run high all of the time. I noticed the following during a 7 mile climb up a significant grade pulling a stacker weighed at about 17500, the highest I got was 217 degrees. I did manually keep the RPMs in the 17-1800 range. It hit 217 briefly twice then backed down. 

Conversely 2 years ago similar grade actually got a little hotter than that without unplugging fan.. 

Question is there a reason to have it run 2 speeds would hi all the time be better not just in the mountains.?