My dad used to do that in "not so cold" winter.He had a short commute and wanted to get some warm air more quickly.

On another hand, I see that a lot of trucks have some materials in front of their radiators to limit the cold air flux in the engine bay.

Is it a good/smart thing to do on our cars?Radiators are dimensioned for hot weather climate, so...If yes, how much will you block? one third? Half?

I was planning using some plastic or cardboard and insert it between the bumper and the radiator.

Is it still a good idea even on long commute (about 1 hour drive)? on long travel (several hours)?

Feedbacks and experiences are welcome

re blocking radiator.

It depends on your situation.

Your Rogue is setup with several temperature sensors to overcome and stabilize outside temperature changes. No blocking needed unless unusual situation occurs. Example- snow drifting into engine compartment overnite may cause running/electrical problems.. I don't believe you are a "Ice Road Trucker"

In the old days radiator caps were the only temerature control device for the cars. On very cold days , the cap would remain chilled even with the radiator hot restricting fluid flow and causing the engine to reach operating temp very slowly. Radiator failure and boilovers were common. Wiring a rag over he cap or sticking cardboard in front of the radiator kept airflow from overcooling the engine compartment. Again, note that back then the fan ran at engine speed at all times, hot or cold.

Answer for average Rogue owners.. Not needed

+1 for what mstrmstr said.

Theromstats and electric radiator fans have eliminated the need to 'cover the rad'.

My dad had a Volvo PV something or other and it had a thin chain that ran from a radiator blind in front of the radiator to the dash. I remember pulling the chain or releasing it depending on dad's watching the temp gauge.