If I manualy turn on the radiator fan, I can get the needle to drop to N.
How do you manually turn on the fan?
Also, I was under the impression that cooler isn't always better, in order for a good burn in the cylinder the engine needs to be at it's "operating temp"; IIRC the op. temp for the Zetec is 192 deg. I have also heard, though I have no personal experince, that water-wetter and our cooling system don't like each other. I f you were running high CR, turbo, or Nitrous; I could see the need for an oil cooler and a cooler T-stat, but just be aware that lowering the op. temp may possibly rob you of a few ponies.
