Which Tstat ?

[red82gt]

"Actually you want the coolant to stay in the radiator longer to cool before it circulates. If the coolant is flowing more often at a lower temp via the stat, then its not cooling down enough, and can actually cause the engine to run warmer."

You guys got it backwards. When the coolant is hot, the thermostat will not hold it in the radiator for it to cool, it will be open. The thermostat holds the coolant in the block to assist it reaching operating temperature (think of the direction of coolant flow and think of where the thermostat is). The coolant will lose more of it's heat when it is moving. The 192* stock thermostat is to assist the motor getting up to optimum temperature for emissions reasons (warmer=more effective catalytic converters). I remeber when a ford engineer made a similar statement in a magazine and got blasted by several people the next month.