the computer will not turn the fan on unless the temp is 215 or the AC is running-the computer turns off the fan at 200. Thermostat will not, in hot weather, change operating temps-when the thermostat opens at 160 it is fully open at 172, when a 188 opens it is FULLY open at 200-so you are just introducing cooler coolant with a 160, but the fan will not run until the temperature sensor gets to 215 and the temp sensor provides that information to the ECM which commands the VCRM to make the fan do it's thing.
Sniper tuners CLAIMED to give you the ability to adjust the ON/OFF for the fan settings, but it was bull:q:q:q:q-a scam, nada. I have a 160 thermostat in now, today it was 93 degrees, in traffic I still got to 215 without the AC running while sitting in traffic, my so-called tuner does NOT change the settings like the bull:q:q:q:q SNIPER 'tuner' (that's funny) claims....I bought a JY fan out of a 93 and am going to wire it up to a toggle and relay so that I can MANUALLY turn my fan on when I sit in traffic in hot weather, since my bull:q:q:q:q SNIPER tuner does not do this...