I idling my car for 30sec or 1 min (when very cold morning) sometime a bit more than that when I have to use bucket water to defost all the windows.
I remember many years ago a TV program have been cover some research in this topic. I'm still remember they said with EFI engine and better oil technlogy we don't need to Idle engine for long period like old carby (with choke) engine.
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