Cardboard radiator cover trick: Outdated method or winter car hack for the modern age?

Cold temperatures continue to be a challenge for some vehicles. Back in the day, drivers frequently applied a trick: blocking the airflow to the radiator with cardboard. But do they still do it?

In 2018, we conducted a survey, asking if drivers still use this method. Interestingly, only 19.7% of respondents said that covering the radiator with cardboard made a noticeable difference in engine warming. Surprisingly, around 7% stated that they didn't see any difference. But why such a discrepancy?

The explanation is simple - it all depends on the age of the car. Modern vehicles are fitted with electrically controlled shutters, which open or close according to needs. When the engine needs to heat up promptly (not only for lubrication but also for cleaning exhaust gases at high temperatures), the shutters are closed, creating a rise in temperature. These mechanisms are crucial during high-speed driving as they help minimize aerodynamic drag.

Is there a practical use for this homemade solution? Yes, but only if we're trying to mask issues with the cooling system. For instance, in cars repaired haphazardly after accidents, the cooling system might fail to work efficiently. In such circumstances, blocking the radiator's airflow with cardboard can be beneficial, particularly when the thermostat malfunctions and remains stuck in the position for a heated engine - achieving the correct temperature can be quite challenging.

However, it is essential to understand that you mustn't cover the radiator directly with cardboard. The cardboard can catch fire and potentially result in a car fire - certainly not the kind of "warming up" anyone desires.