Sure I can write about it with some technical terms, my internal combustion engines mechanical engineer degree might help here
But... They know it pretty well and they did it on purpose. Their explanation would be:
We run our engines at 105C just bc of higher emission standards
which is total BS. They will also say that their tstats are so advanced so they can open it whenever they want, but they don't tell you that that boiler doesn't work that fast and very often dies (you won't even get any CEL if boiler died).
Myth 1:
Bc of emission standards.
Sure higher combustion temp will help to burn it faster, but there are some limits there!! Did you notice that in summer time your car is kinda slowish??? Well it's all bc of detonation going on inside the cam!!!
Bmw has knock sensors which adjusts timing on the fly so you cannot hear any detonation. And yes you can easily put 87 in your engine and you won't hear any knocks, only reduced power. Sooo high temp in your engine will prematurely kill your pistons and rings and head gaskets.
Yes it's amazingly can sustain that heat for a while and later we get blue smoke lol
)
Myth 2. Higher temp will get you more power:
And here is some nonsense from bmw: every S V8 engine for m cars still runs at 79C max!! for example S54 runs at 78, s62 at 79 and this is the same V8 and V10 technology as M62(runs at 105).... So wtf??? And all these m cars have same catalytic converters!! And it's all fine with "high emission" standards!!! And M cars actually last pretty well even with the way they are being used on the track!
S54 can easily make 200km without any serious problems related to cooling!!! And more importantly all these sporty tstats don't have any fancy boilers inside, but why? what about higher temp will get your better combustion theory??? And M cars have way more power than standard 105C engines. Ever thought why bmw engines from 90 still running okay without smoking even at 300-400k miles and don't forget that inline 6 with 4 valves per cylinder still makes 25-28 mpg hwy??? Ok it was from bmw stand point. Other car makers still have 90-95 tstats (Mercedes, Toyota, honda, ) but wv took the same idea from bmw and they have 100-105C tstats starting from 1998 and look their engines cannot even make to 60km!! Literally Oil gets cooked on those oil passages!!! So many failures!!!! Read about 4 cyl turbo engines recalls. Though at least V8 run at 92 so premium cars are ok.
So why all other cars are ok with normal tstats and they all comply with emission standards pretty well????
At least bmw didn't do the same thing for inline 6 engines so the best selling 5 series are at lower risk bc it's 95C, otherwise nobody would buy it!!! Wtf 8yr old e60 costs more than e65?? E60 with V8 has horrible reputation everywhere!!! Ppl are scared to death of those N62 and M62 time bombs. Oops and one more thing: that 105C from 2001 is still the same even for 2012 engines!!! I can only imagine how long those turbocharged engines with 105 can sustain, it's like suicidal for the engine.
yes it was very little from internal combustion theory.
Here is some thermodynamics:
As you all know water inside the hose is pressured about 200psi which is HIGH! They did it that way so the water won't be boiling at 105-110C but as you all know any high pressure will put the system on the edge: all hoses, all gaskets are at high risk of failure!! That's why we all sooner or later will get coolant pipe leak and other leaks!!! And tiny leaks are not easy to find on the car bc when you drive it there is lots of vibration and therefore you might get some air in the system easily, that's why they built self bleeding system which removes air every time it gets there. It only works if system is perfect.
And therefore bmw recommends 2-3 yrs cooling system overhaul (pricey). Ever thought why Toyota needs it once in 10yrs??
And high temp will kill all rubber gaskets very quick.... Every single fking gasket leaks in 105C engine even with 50km plus any oil leak from the engine will kill your suspension rubber bushings easy. If you look at inline 6 with 200km it would look pretty good.
Oh almost forgot: high temp will kill your tranny as well bc tranny cooling is linked to the main radiator!
My conclusion is that if we had 90C tstats in our V8 would outlast any similar engine bc they are built to sustain that crazy heat for a while already! Mpg would be still the same if not better, think about it how much power that huge aux fan uses every time???
In other words if you buy new bmw with V8 or V12, retrofit tstat to 85-90C , put only 0w40 synthetic oil, do 5000mls oil change, you can easily make 200km without any serious problems!! Btw my 95C tstat will fit any brand new bmw. And Toyota and lexus would suck bc they are far away from technology and handling stand point.
But the problem here is bmw won't make any money from rich ppl.... You think rolls Royce ppl would complain about it??? They will just get a new engine and tranny swapped every 100k miles
btw at least rolls Royce has bigger radiator and tranny cooler, but still the same 105C design.
Having 105C tstat is like playing with the fire: you never know if your coolant is boiling