I can't imagine its computer being happy all of the time with a 180 degree thermostat. Not to mention running a cooler thermostat won't help the engine run cooler on a hot day, it will just run cooler on a really cold day which isn't what you'd want. I'd stick with the 195 degree thermost the computer was programmed around. And stay away from a fail-safe thermostat, they cause more problems from getting hung up wide-open too easily than they solve.
