Quote:

The thermostat doesn't control the high end of the temp. If you run a 165* stat you shouldn't expect the engine to run that temp. All the stat does is slows water flow until the engine reaches the stats open temp. If the engine runs above that,which most normally do, the stat will never close.

Right, I stand corrected and agree. The t-stat controls the lower end and the cooling system design controls the upper end. The t-stat just doesn't let it get below the spec temp.