Is there a relationship between the Actual Fuel Rail pressure and the amount of fuel required to propel the truck down the road? I am debating this with myself as to whether I can prove that fuel rail pressure can be tuned up to run at a higher level and actually increase the fuel economy. I have sucessfully raised fuel rail pressure and decreased the required pulse width to idle esp. This in theory (kinda) would prove the be a sort of control for the experiment.

My problem is proof. I have to have a computation on what happens at the injector level when FRP is increased 10% or even 20% at idle. 30-35 etc etc. If my injector pulse width is decreased the same 10% or 20% did I even gain anything in terms of a decrease in the amount of fuel used. I know that as you increase pressure, flow is also increased. If anyone can help me out on the injector fuel flow data at different pressures I would appreciate it.

I also have to figure out how timing plays a part in the fuel rail pressure equation. I know it's the same as adding timing.. or so I was told. I have an older FRP-PW-Timing calc.

Part 2 is if frp even matters, or if it can be tuned better with timing to control cylinder pressures for the same economy. At a point you can't get blood from a turnup.