The Digital Fuel Meter is a new, low-cost, easy-to-use device that measures actual fuel use. The DFM simply plugs into the diagnostic connector under the dash where it gets fuel flow information directly from the engine controller without the need to modify the vehicle. Meter generally has a digital display or signal output. Such as turbine flow meters, gear flow meters. Fuel meters are an important component of fuel transfer systems. Digital Fuel Meter is very useful and made for commercial uses.