[MetroMPG]

A compromise between finding & installing a fuel flow based meter (instant feedback) vs. tank-to-tank MPG calculations (feedback may be too slow for those trying to evaluate mods) is to calibrate your fuel tank sending unit and effectively create a "trip gauge".

- With your tank nearly empty, connect a digital multimeter to the fuel tank sending unit (measuring resistance)

- Add a small measured quantity of fuel (say .25 gal)

- Note the change in the multimeter reading

- Repeat until tank is full (multimeter reading stops changing with added fuel)

Now you have a graph with decent resolution of fuel level vs. sending unit resistance, which you can use to figure out fuel consumption. (Assumes you park in the same spot as when you calibrated the sending unit... and the sending unit isn't sticky etc. etc.)