[BigLew]

Hey fdheld34,

This is just my 2¢.

To the best of my knowledge, the standalone fuel flow gauges give you gallons per hour information. If you want to convert to MPG, you will need to divide your speed by your fuel flow. That said, there are some systems which will take a NEMA input and use it to calculate MPG. These systems are generally high end, multi-parameter chart plotters with depth sounder, radar, fuel flow meter, and general engine instrumentation capabilities. You are talking into four figure's of cost easily. MPG is a nice number to know, but it is not something you need on an ongoing basis. If you have any flow meter and a GPS, you can calculate at the end of the day MPG if you use total gallons used that day and total miles traveled.

Fuel flow is generally more useful in adjusting engine speed, trim and weight distribution. You can simply see the results more dramatically.

As I said, just my opinion. Good luck.