Higher or lower degree thermostat?

[steve g]

I read an article recently on solving overheating issues. It stated that the optimal temperature differential between the coolant in the block and the ambient air temperature is 100 degrees and that a higher degree thermostat with the appropriate pressure cap will cool better than a lower degree thermostat. In other words, you need to hold the coolant in the block longer to create an optimal temperature difference when it returns to the radiator. Can this be correct? I've had overheating issues so I tried going with a 160 degree thermostat to keep the coolant flowing sooner. But according to this theory, my coolant isn't getting a chance to transfer as much heat from the engine before it returns to the radiator. At idle my temps continue to climb and the dual fans and aluminum radiator can't keep it in check.