What is the normal operating temperature range for an engine equipped with a 195°F thermostat?

The normal operating temperature range for an engine equipped with a 195°F thermostat is typically between 195°F to 215°F. The thermostat's primary function is to regulate the engine's temperature by controlling the flow of coolant to maintain optimal operating conditions. When the engine reaches the thermostat's rated temperature, in this case, 195°F, the thermostat opens to allow coolant to circulate, helping to dissipate heat and prevent overheating.

In general, an engine running consistently above the thermostat rating could indicate excessive temperature, while lower temperatures can lead to inefficient operation and increased emissions. Therefore, the selected range aligns with common automotive guidelines, where the engine is designed to operate just above the thermostat rating for effective thermal management.

For example, a vehicle’s engine should reach and maintain temperatures that support proper fuel atomization, efficient combustion, and effective emissions control without excessive heat that could cause damage or wear. The other options suggest temperature ranges that fall outside of what is typical for a 195°F thermostat, either being too low or excessively high for an engine’s stable operation.