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Again, I'm not seriously recommending that anyone do what I do (switching the fan on and off manually), as that is a defiantly 'bronze age' approach, but it can teach a lot about what stresses these engines - and what doesn't.
You'd think climbing a long, steep hill would drive the oil to its hottest, but that's often not the case. I usually downshift and sometimes let the revs climb to the high 3000's on steep grades. Leaving the oil cooler fan off, the oil temp will often drop as the engine fan spins way up all the way to the top of the hill. The sainted German engineers did understand a lot.
Also, just noodling around in traffic at slow speeds on flat terrain - with the engine sounding very unstressed - will sometimes start oil temps climbing. If the fan were on a thermostatic switch, you might miss subtle changes like that.
Driving this car is a kind of tap dance for me. The engine is always happiest in one particular gear, and the gearbox seems to prefer careful rev matching more than most modern ones, so driving smoothly becomes a sort of game. Paying attention to what the engine needs means constantly watching the tach and temp gauge, so switching the fan on as required becomes just another part of the dance.
And it's not like that is a constant task. On most days, the fan gets turned on at some point and stays mostly on after that.
I got this car because I wanted something that wasn't a Toyota and, on balance, that has worked out pretty well.
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