When, say a 165* thermostat, reaches operating temp (165) it opens. However the engine water still continues to heat until the engine (not the thermostat) reaches its operating temperature. It is air/water flow that determines how warm the engine gets. Many folks in the warmer regions would take the thermostat completely out and the engine would operate just fine as long as there was air flow and water circulation. Yes the thermostat will have an effect on engine temps but unless it’s defective and won’t open it shouldn’t be the cause of a overheating situation. The main point to my post was the OP’s concern over 185 degree operating temp being too hot. Unless it continues to climb, 185* will cause no harm. Note; I’m not a scientist so I cannot provide the answers to Tim’s questions just real world experiences.
