Increasing Fuel Pressure...effects?

Hey guys,
I was wondering, I know increasing pulse width throws off the DIC MPG reading but will increasing fuel pressure do the same thing? Also, anyone that's messed with fuel pressure, what has been the positive or negative effects? Will the truck actually increase pressure or will it merely reference the fuel pressure table but ultimately end up using whatever pressure it needs to accurately deliver the fuel commanded....I have my suspicions that this may be the case... thanks guys!

Also, a little off topic but what tires are you all using on the drag strip? I was looking at buying a pair to swap out on the rear for better grip to avoid much 4wd launching... thanks :cheers:

increasing fuel pressure without adjusting the PW will NOT screw up the DIC. the DIC make mpg calculations based on known flows rates for FP and PW. so if you change the desired FP at a certain RPM and TQ request the tables have already been adjusted to lower the PW to give you the same actual amount of fuel. Adjusting the PW "fools" the ECM. and it makes it mpg calculation based on what in knew for that givin FP abut now you are sending more fuel that what it thinks, hence the HIGHER mpg reading that what you are actually getting.

Okay that makes sense. So what happens is increasing the fuel pressure narrows pulse width to maintain the same final delivery amount, and so a narrower pulse and higher pressure will deliver the same fuel but in a finer spray essentially? So perhaps it would give a slight increase in fuel economy...

opinions vary depending on who you talk to. some say parasitic drag by the high pressure off sets that and some say its better.