It will take longer than five minutes with no load, I agree that it is about five minutes with moderate load. But even assuming five minutes, those five minutes running a cold engine with no load will be the highest wear rate your engine will ever see, far harder on the engine than wide open throttle at full load. And yes, that considers that you are using synthetic oils that flow at that temperature.

The objective of driving the vehicle as soon as you have oil pressure is to minimize the (necessary) warm-up time.

If absolutely necessary to warm the interior, buy a car-warmer that plugs in. Just don't use an idling internal combustion engine as a space heater, it is not good for the environment or the engine.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue