The fact that engines are designed so that coolant and lubricants can mix has always left me a bit suspicious of planned obsolescence.
I think realistically it’s a limitation of the casting process, but it is to me the dumbest part of internal combustion engine design. Point the channels in two different directions on the casting, and only a cracked block should allow them to touch.
You should watch videos on how hard head gaskets are to design if you want an idea of some of the engineering involved- I think "engineering explained" did one recently on youtube.
What I’m saying is, should we still be building engines that rely on “the” head gasket to keep fluids separate?
An engine cylinder at a minimum must deal with: lubrication, fuel, and gasses. The exhaust manifold deals with half of the gases. I can’t recall if common rail injectors are still technically part of the head (I can find pictures where the CRI system sits on the head, with separate gaskets, but I’m not a mechanic).
With modern manufacturing would we not be better off splitting these tasks up so that only a cracked engine block can mix fluids. Not a torn gasket, not a warped head, not a thrown rod (though rods are going away too).
but that is unrelated. Automatic transmission fluid isn't circulating through the engine on any vehicle by design that I have seen.
Plenty of vehicles with a standard gearbox just use the engine oil as the transmission lubricant. In motorcycles this is called "unit construction". I've heard of some older Saabs that did this as well.
because the mixing the article talks about it transmission oil and coolant.
When a passageway cracks in a cylinder head & engine oil becomes "milkshake" that is the mixing of engine oil and coolant. Two separate kinds of oil in different places.
I think realistically it’s a limitation of the casting process, but it is to me the dumbest part of internal combustion engine design. Point the channels in two different directions on the casting, and only a cracked block should allow them to touch.