I never meant to insinuate ignorance. We both were disucssing mutliple things that weren't exactly to related to one another.
You state an IC engine is always most efficient at WOT. This is true, but there is one provision. It is only most effiecient when it is at WOT and at the peak of the toque curve.
If RPM is lower and at WOT, then the engine is not operating at the most effiecient state. Closing the throttle will improve thermal efficiency because less fuel is being wasted.
Closing a throttle does not necessarily reduce overall thermo efficienciy because you are reducing the amount of fuel being consumed and possibly (depending on engine design) leaning out the mixture. YES, it does reduce volumetric efficiency, but VE is related to the MAXIUM amount of power and engine can make.
Themal efficiency is not effect as much as you think by closing the throttle because when less air is going trough the engine, less fuel is being burned. In the real world (outside of all our theories) at WOT an engine is usually running pretty damn rich...this is less than optimum fuel ratio and therefore less efficient.
In the end, I'll agree to disagree
