Application calls for 195 degree automotive thermostat can you use 180 degree thermostat?

Using a 180-degree thermostat in an application that calls for a 195-degree thermostat may lead to the engine running cooler than optimal. This could result in reduced fuel efficiency, increased emissions, and potential issues with engine performance, especially in colder conditions. It's best to use the specified thermostat to ensure the engine operates within the designed temperature range for optimal performance and longevity.