There is no firm consensus on this.
So just like the 3000mile OCI or dumping the factory fill, people are entrenched into their positions and do whatever makes you feel better.
However I'll explain the argument and theory of the other side. Take it or leave it.
I will claim that no owner's manual says you need to idle to warm it up. If you disagree, please find an example from a modern car (i.e. fuel injected with computers and smog controls).
Some manuals give the exact opposite instruction regarding cold startup and not only say there is no benefit to idling to "warm it up", but tell you instead to go immediately drive at a slow/moderate pace which actually warms the car up faster.
This doesn't mean jump to a high load immediately or drive if there is another reason why car is not yet safe to drive (frozen windshield, brakes/gears don't work right when cold, etc), but I'm just talking about the engine and the imaginary cold "damage".
If you have such an extreme cold temperature where the "cold" oil is causing damage, idle versus driving at a slow rate is going to cause the same damage. If the engine is running at all to perform the "warm up" it's doing the same damage whether it does it in your driveway or at low moving speeds.
What some manuals will say you that if you are in EXTREME cold, where the engine damage could occur, you need to install a block heater or alternate means to do the "warm up" before starting the engine at all. But idling to do the warm up isn't going to prevent damage
If you want evidence in the form of a thought experiment, think what does the car do on a cold start? It idles faster not slower.
If cold was "damaging" from lack of "warmed up oil" you'd expect it would have to run at a slower pump RPM and startup sequence to pump and flow the oil(like some airplanes) before the car actually fires up the engine.
Since there's no separate sequence, same "damage" occurs at idle versus getting on with it. You could dissect whether the damage is actually less because the idle is more to just barely keeping the car on, versus actually warming it up.
Not saying go out and race vin diesel for slips or motor up pikes peak from cold start, but if the car "wants" to idle at 1500 to warm up faster, 2000rpm and gentle driving will achieve that goal even better.
Take it or leave it; idling won't "hurt", but it may not really help you other than piece of mind.
Check your owner's manual see if they say anything for your car. That's a more definite precise source versus yahoo's on the internet.
