sunfire temp gauge

[clyde23]

for the last six months my temp gauge needle is running at the 3/4 mark while highway driving and goes to the top of "normal when driving in town. Also if I speed up to 12km per hour the neele goes down to the middle of normal. changed the temp sending unit and thermostat still the same....any ideas? Mechanic said it was running a temp of around 195F which he said is normal....