Originally Posted By: Miller88
It makes the car warm up slower. I turn the heat off and let it warm up. Then when I get in, I turn on the heat and instant warm air.
When it's -40 out, you won't be trying that. An extra half minute or whatever small amount of extra warmup time needed is irrelevant. The car is supposed to make me comfortable, not the other way around.
As KrisZ states, I prefer to leave it on defrost or defrost/floor if it's outside and I have to warm it up. I, for some inexplicable reason, turned my heater off in my Town Car with the remote starter one winter day. It was ridiculously cold. The engine was nice and warm when I got in, but the interior was decidedly not preheated, and breathing on a windshield when it's -40 and the interior hasn't been heated doesn't help visibility at all.