All, as a newer CFI I've gotten into some 'technique' questions as I've taken over for another CFI that's left.
It was probably a 32F day here in west texas. A student pulled out his 172. We preflighted and started the airplane. The oil pressure came up immediately, but what puzzled me is the student wanted to run the engine for an extended period of time below 1000RPM to let the engine 'warm up' because the oil temp was still cold.
Now, recent research on cars has shown that idling the car more than 30 seconds to let it 'warm up' is a fools errand, but I'm willing to concede that airplanes have different engines than cars.
It is of my opinion that starting an engine and sitting there for 5 (literally) minutes won't help the engine get warm. In my opinion it's the runup that will get the airplane temperatures where the want to be, and if the temps still aren't up by the completion of the runup, we will continue to idle at an increased RPM (1000-1500)
I'm not sure where I got my ideas of engine management in this regard, but another instructor has instructed students not to let the airplane move from the start position until the temps are in the green. How is that ever going to happen at 800RPM?
Would love opinions on this, and discussion related to engines other than O-360s is valued.