Sorry for the late response, I'm reading Qlist posts in reverse (there are a
lot of them!)
I can see why auto manufacturers don't recommend "warming up the engine".
When the engine is cold, it needs a richer mixture to run, especially at idle.
So the FI system might be dumping quite a bit of gas into the cylinders,
leading to inadequate lubrication of the rings. Add that to the fact that
many people drive their cars for short hops where the oil temperature doesn't
get hot enough to evaporate the gasoline, and you also have diluted oil. Do
that a few dozen times and you are asking for premature wear.
If you start the car, make sure it's running right, and then drive it gently
while the rest of the mechanicals gradually come up to temperature, you will
probably be treating the car better than if you let it sit for 3-4 minutes
cold at idle, dumping a rich gas mixture into the cylinders that has no chance
to burn.
Also, "letting it idle" doesn't warm it up faster than driving it. In a no-
load condition, the engine isn't going to warm up as quickly as it will if it
is moving the car. As long as the thermostat is fine, the oil is flowing, and
you are gentle with it for a few miles, the engine should warm up faster than
it would if it were sitting still.
The posts about the caveats of the hydraulic system are well taken. I am
gentle with the steering and brakes until everything is at least lukewarm.
Best Wishes,
Alex