If you are evaluating air intakes the MAP signal at wide open throttle should be one of your best buddies
But the MAP signal should be corrected for current weather conditions and altitude
On fuel economy
the MAP output is also of great value
If the MAP output is telling you that there is less than 75% of full atmospheric pressure to "push" the piston down on the intake stroke
you can improve your fuel economy by any of the following:
shift to a higher gear to lower RPM
cut out cylinders like Chrysler MDS
add a bit more exhaust gas recirculation unless it causes spark missfire
lean out the air/fuel ratio
heat the air intake