[ragingrobot]

This has not been necessary for quite some time. With modern tolerances in manufacturing, it is not necessary, even wasteful (burned gas and small amounts of wear that add up over time) to warm up a vehicle.

It may have been another story at long ago with larger gaps between rings, differential expansion of materials, newer oil formulations and so on.

With my daily driver 1995 Grand Prix (which just a few weeks ago bit the bullet, non-engine related), I never, even in the coldest weather let it sit idling warming up. Most mornings even around 0F, I turned the key and drove off. It died with ~289,800 miles. It did not consume any oil or coolant, the spark plugs are clean as new.

In fact, driving off easy will warm the engine up faster than letting it idle.

[Schiendelman]

My partner’s 2017 Subaru asks us with an indicator to let it warm up on cold mornings.

[ragingrobot]

Interesting, I have never seen such a thing. Perhaps it's more for comfort than mechanical reasons?