I do not use any thermostat from May to November (removed-full open-free flow); and install a 180F in the in-line housing, two screws, 1 minute job the rest of year. The bypass coolant path is non-existent for 12 years now. Many perhaps do not like it.

 

170 if you have a 1999-2002, 180 if it is 2003-2004