If the 80 degs reading was obtained from the ECU diagnostics with an OBD tool rather than the ornament on the dashboard when the engine was up to temp I would say that it was too low. The Duratec is designed to run hot at around 100 and even above. A genuine 80 deg water temp at the head sensor might imply that the stat was stuck open. I wouldn’t take the gauge too seriously but check the ECU live data if you want to be sure.
