I read that vehicles over the last 20 years have increased operating temps by

[Qaiphyx]

roughly 20-40 degrees! Thats seems like a fairly large increase to me. The reason was to benefit and better utilize fuel injection systems, however, the steel is now potentially at weaker temperatures. What would most likely be the ideal operating temperature for engine blocks such as, steel, cast iron, and aluminum?

Or maybe to better ask the question, at what temperature would this metals withstand the most psi?

 

[rcgldr]

Thermostats went from 180 to 190+ degrees farenheight for a while 10 to 20 years ago, but since catalytic converters they're back to 180 degree thermostats again. The catalytic converter gets really hot though.