The last thing the water sees before it goes to the radiator is the thermostat......so when you go from a 180 to a 160 deg stat, that means the water exiting the engine is now 20 degrees cooler (roughly speaking) and all other cooling IE trans cooling and engine oil cooling have been accounted for.

So to my way of thinking, when I put in a cooler stat, I not only dropped engine temp, trans temp and engine oil temp but the under hood air temp dropped also. I think the F150 is one of the few vehicles left on the road with enough cooling capacity to accomplish this feat.
Dale

 

I'm also in the process of installing the monster 5,500 CFM Flex-a-Lite fans and a 170 tstat. That oughta do it.

 

Well not really because this is after it has gone thru the rad.It is picking up the heat IN the lower rad hose and going into the motor from there so the inlet water temp AT the water pump is higher.If you were to measure the water temp at the inlet of the lower hose[just leaving the rad]and measured it at the inlet of the block[alum adapter on the block]there would be a difference in temp.Stan