Volumetric efficiency varies with RPM, as noted by an earlier post. Its not just a inversely proportional relationship, as there are sympathetic harmonic effects in the intake and exhaust which can and do apply.
I have gotten the impression that the PCM contains a table which has the VE as function of RPM. But I have never come across a means for accessing it.
Regardless, I'm wondering if the instantaneous VE is reflected in the intake Manifold pressure (MAP). For example, let say @ 1000 RPM, the VE is 70% but drops to 65% at 2000 RPM. Is the MAP value different than it would be if the VE was a constant?
Given that the previously defined equation for calculating MPG based on MAP, is it enough to make the VE a constant at, in this case, 70% and then rely on the MAP to factor in VE changes with RPM ?