Optimal temp question

Was just looking into the optimal engine temps. Seems the prevailing wisdom is the optimal temp range is 190-220F. Why does almost every vehicle have a thermostat that's 180-190F? Wouldn't that be too low? During regular driving, my Tundra never gets above 186 or 187. Am I missing something?

 

The coolant is cooler than the engine and oil. Safe to say when the coolant reaches close to the thermostat opening temp the, oil is above boiling point for water or we would all have milky oil.

 

I think the hottest I've seen mine get is around 208-210. Most of the time I'm around 185-190.

 

Really ?....I feel a friday poll is in order

In all seriousness, a well maintained 2UZ would not come close to 220 deg, at least not in my 04 with an OEM thermostat rated at ~186F. Most of my recordings at idle are usually 187 even if ambient temp is for instance 90.
BTW....where was this "prevailing wisdom" ?
Granted I don't see every post but most of the ones in this forum speak of 185 +-10 and the FSM says 80 − 84°C (176 − 183°F)

 

According to my Scangauge II, my '02 V8 has always run 182 to 184 (Cooler Weather) and 186 to 188 (Hotter Weather). I have seen 192 idling in Traffic (Hot Weather).