Nigger, get a fucking coolant heater and a timer. Instant heat. As a mechanic, I've come across a large number of "I let it idle to warm up" engines that had severely scored cylinders (low oil pressure), warped heads (localized hot spots) and the associated bad head gaskets and gummed up intakes. Way fucking easier and cheaper to use a block heater, coolant just being my preference. And BS on letting the engine idle before use. Engines warm best under load (use), you shouldn't Hammer on the engine, but between casual driving and idling, driving is the easy winner from both the theoretical and practical sides.