It has always been my preference to let my car warm up for a couple min or so when its very cold outside. Sometimes I have to do it to melt the ice away but also to warm up the oil and the internal parts of the engine. I am seeing more and more people saying you don't have to do this and it can actually damage your engine. They claim that the rich fuel to air ratio that your car needs when its cold can wash off oil from cylinder walls and leaves them without oil. Is this true? Don't manufacturers take the measures to stop this from happening? Because of this they say its better to just drive right away, which will warm up your car faster than idling.