You are very correct about running too cool.. There is a threshold built into
the programming. That's why a 180* should be just fine , esp in warmer weather/climate
The engine will usually run several degrees above the "regulated" amount, depending
on the capacity/condition of the cooling system
Now a 160* , if cooling system is very good, would cause issues with fuel enrichment'
unless you changed the temp/fuel tables in the pcm
In my case, in my old chevy , the computer looks for the 160* as the "normal"
operating temp and fuel enrichment for a cold engine is turned off above this
In our late model LS motors, you would have to do the same if you actually were
able to run that cool. But, in a daily driver (not race)... Running 160-180 would
shorten the life of the motor quite a bit. Everything is set up to run around 200*