Warming up car

This is a loaded question, very hotly debated among car folks.

My personal opinion is that it is better to start the car and let it warm up for five to ten minutes if it is cold outside. Like below forty degrees F or so. DO not rev the engine. That is not a good thing. Just let it run a bit.

Why? Running it warms up the engine some, that promotes oil flow because the oil will thin out as it heats up and allows the coolant to start circulating and heat up the interior some. It also means that you should have heat faster to keep the windows clean if needed. It can also allow a problem like bad gas/water in the fuel to show up while the vehicle is is a spot that should not be an issue if the engine were to stop running because of those. Not like you were driving it for five to ten minutes and now breaking down on the side of the road.

My idea of cold is going to be different than others. That is all dependent on your location and what you think is cold.