There are no functional differences in fuel flow parameters indicated between these systems. All of the JP Instruments Engine Monitoring Systems with the fuel flow option will indicate all fuel quantity and navigation based fuel indications (when interfaced with GPS) that are included in the the FS-450 Fuel Scan Computer. The engine analyzers with the fuel flow option contain a 3 position toggle switch with positions for EGT, ALL, and FF. In the EGT position the numerical display indicates only temperature related parameters and bus voltages. In the FF position, the numerical display indicates only fuel flow parameters. In the ALL position, the numerical display, indicates parameters for both EGT and FF. The bar graph display is not affected in any of the positions nor are the alarms for the engine monitoring system. The FS-450 was designed as a budget, stand alone fuel computing instrument.