Chief, Yup, ganung-ganon po ang ginagawa ko. Anyway with your question, no hindi po sya gumagamit ng coolant if the engine is OFF, better cool down while the engine is running, at least with this practice, you're sure that you are cooling the engine as a whole not only the water inside the radiator.
Sa question po ni sir Tepperz, actually wala naman po masisira if you will immediately shut-off the engine, but doing those practice will prolong the engine life. Why? actually madami po benefits, like reduced oil burning, limiting or minimizing the engine metal parts contraction, and etc. Minsan nga po natanong ko sa sarili ko, why does (mostly) turbo charged engine have turbo timer (although wala po turbo oto ko he he!)? it is because since turbo engine operates on a higher temp, needs to cool down to preserve or protect its internal parts.
