It is important to choose the right ratio between the amount of coolant and water for a given weather. You cannot add only water to the engine. Freeze resistance is reduced by both insufficient and excessive amounts of coolant in the mixture.
Note: Coolant temperatures reach very high values when the engine is running. If you need to add coolant when the engine is at operating temperature, loosen the expansion tank cap slowly and carefully to relieve excess pressure.
On vehicles equipped with a diesel particulate filter, the electric fan can operate for approximately 10 minutes after the engine has stopped.
Please note: A new car contains a liquid that does not freeze at temperatures down to approximately -35°C.
The need to frequently top up the coolant indicates a fault in the system. It should be identified and corrected as soon as possible. Remember that overheating the engine can cause damage (crack formation) cylinder heads.