Oil: I'm supposed to put Exxon 2380 oil in this airplane and it goes all around and makes things slippery, cooled, cleaned and sealed. Done. Yeah, right.
C'mon, Aviatrix, it's not that bad. Half an hour on the oil system and then you can go play with your toy flight simulator. Minimum oil temperature for start is -40. You don't need units there, the Fahrenheit and Celsius scales cross at -40. I'd be cross, too. In addition to the standard four functions of oil referenced above, oil pressure on this airplane takes part in propeller operations, specifically normal blade adjustment, negative torque sensing, and the unfeathering pump. It's used in three parts of the anti-icing system, and it has gauges and annunciator lights associated with it.
Oil lubricates the reduction gear, so that the propeller rpm can be 2000 instead of the 42,000-odd rpm of the main engine, and oil pressure in the propeller hub drives the propeller towards fine, against the pressure of the feathering spring, using the usual system of flyweights governing a pilot valve to keep the propeller on speed. Feathering dumps the oil from the hub, allowing the feathering spring to drive the blades all the way to 89%, while negative torque adjusts the blade angle to windmill in the 18-28% range, waiting for the pilot to either feather or attempt a restart. It's a kind of half-hearted autofeather.
Anti-icing has already been described, oil circulates in the oil cooler inlet lip, and then if its temperature is still above 55 degrees it goes to the oil cooler, else it goes through the filter and back to work. Fifty-five is the oil's lucky number because that's also the pressure differential across the oil filter that will cause it to bypass the filter. Oil heat also anti-ices the lower part of the engine air inlet, provides the heat for the fuel anti-icing heat exchanger, and makes the airplane nice and warm if you put your hands against the nacelle after shutdown.
Would you believe that that took me thirty minutes? It did include going off to get another book to look at a diagram of the propeller system. I need to know more than this, but I need a break.