here is a real live running compression waveform
1996 BMW
idle then WOT snap followed by decel back to idle , pressure amplitude in psi in the vertical scale , time in horizontal scale
engine is running but there is no combustion in this cylinder as pressure transducer is threaded into spark plug thread .
injector is disconnected
pressure peak at WOT exceeds 4x pressure peak at idle
the pressure transducer is calibrated to local ambient baro so 0 psi = local ambient baro
this real time test seems to disagree with your theory regarding pumping losses ....
real world EGR gains to FE also disagree
why ?
[QUOTE=mort;288351]
I posted some stuff in a thread Doug Miller started about efficiency.
To sum up. Pumping losses are less than 5% of shaft hp upto WOT, where they go toward zero. The loss of efficiency is simply thermodynamics. For an engine throttled down to 20% and a compression ratio of 8.5 the effective CR is 1.7:1. So at full throttle the maximum (Carnot) efficiency would be about 57% but throttled about 20%