The thermostat is a key element of the cooling circuit: it regulates the circulation of coolant according to engine temperature, thereby ensuring optimal temperature rise and protection against overheating. On the Seat Leon 1P, failure of this component can lead to thermal regulation problems that can durably affect the engine. As part of the restoration or maintenance of a Seat Leon 1P classic vehicle, replacing the original thermostat is an essential step to preserve the mechanical reliability of the vehicle. This new thermostat provides a direct solution to restore thermal operation in compliance with original specifications.