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