Calculating Fuel Econ. from pulse times and mph

[Roger Heflin]

Hello,

I have been trying to calculate fuel econ. from injector pulse times.
I have a batch fire vehicle, I believe I know what the number of times
per rpm that the injectors fire.  I think the injecotrs fire once per
rpm (is this right).  I know the injector rating (lb/hr), there ford
svo injectors which I believe means they are rated at 39 psi, my car
is running at 45 psi, so the injectors are doing 45/39 * 30 lb /hr.
Also the computer says the injecotr is on x.x ms.  I am assuming that
is what the computer it telling the injectors to do.  Are the ramp
up and ramp down times similar enough that you can assume that that
time is close enough, or are there some transient things that cause
the actual open time to be less than or greater than that number?
What I am really tring to do is figure out what the absolute best
gas mileage my car could get, if it was only crusing, with no braking
or acceleration, and also determine how badly different things affect
the gas mileage.  
				Roger Heflin